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Agilent 6820 Gas Chromatograph Operation

1. FRONT DET NPD FRONT DET NPD Adjust Offset Temp not ready 30 30 Output Output 0 3 0 3 Bead voltage Bead DetTemp wait lt 150 lt 3 Detector on waiting for oven and or detector to reach temperature setpoint and equilibrium When the detector temperature exceeds 150 C the bead begins to heat while the oven and detector reach setpoint and equilibrate 4 Detector on during adjust offset and equilibration time When the detector and oven temperatures reach setpoint and equilibrate the Adjust offset process begins The bead voltage is increased until the output is close to the Adjust offset value Equilibration time see the next page begins 5 Detector on and ready When the Adjust offset value is reached and the equilibration time has passed the Adjust offset line is Off Your detector is on and ready Aborting adjust offset Press Delete with the cursor on the Adjust offset line This cancels the adjustment without turning off the detector gases and bead voltage This is useful if you wish to start a run before the bead equilibration time is passed 6820 Operation 185 Additional Information for Method Developers CAUTION Turning off the detector If you turn Adjust offset Off at any time the bead voltage turns off CAUTION Setting adjust offset on the clock table You can use the Clock table feature to turn the Adjust offset on at a specified time It is not recommended that you Adjust off
2. 176 6820 Operation 6820 Operation CAUTION Additional Information for Method Developers Table 28 TCD FID in series installation Gas Flow rate mL min Carrier helium 30 TCD switching flow 25 FID hydrogen 45 FID air 500 The nickel catalyst tube can be damaged by exposure to air Temperature The nickel catalyst tube is usually mounted in the back inlet position and controlled by the back inlet temperature setpoint For most analyses set these temperatures e Nickel catalyst tube 375 C e FID 400 C Thermal Conductivity Detector Because the TCD does not destroy the sample during the detection process this detector can be hooked up in series to a flame ionization detector or electron capture detector Conditions that prevent the detector from operating Three common conditions can prevent proper operation e Detector temperature set below 150 C e Broken or shorted filament Reference gas flow is zero or Off Filament passivation The tungsten rhenium TCD filament has been chemically passivated to protect against oxygen damage However chemically active compounds such as acids and halogenated 177 Additional Information for Method Developers compounds may attack the filament The immediate symptom is a permanent change in detector sensitivity due to a change in filament resistance If possible such compounds should be avoided If this is not possible the filament may have to be replace
3. 6820 Operation 6820 Operation Setting the Operating Parameters Configure your LAN communications The 6820 GC with LAN communications can set its IP address using the keyboard or receive an IP address from a DHCP server To enter the IP address using the keyboard 1 Press Options Scroll to Communication and press Enter This screen appears Communication LAN CONFIG IP address 000 000 000 000 lt Gateway 000 000 000 000 2 Enter the IP address for your 6820 Enter the numbers separated by dots and press Enter The GC displays a message instructing you to power cycle the instrument Do not power cycle yet 3 Press Clear Scroll to Gateway Enter the Gateway number and press Enter The 6820 displays a message instructing you to power cycle the instrument Do not power cycle yet 4 Press Clear Scroll to Subnet mask and press Mode Type Scroll to the appropriate subnet mask from the list of modes and press Enter The 6820 displays a message instructing you to power cycle the instrument 5 Power cycle the instrument to apply the LAN setpoints to the card 6 Press Options Scroll to Communication and press Enter Confirm that the correct setpoints are present 71 Setting the Operating Parameters To use DHCP to provide the GC IP address 1 Press Options Scroll to Communication and press Enter This screen appears Communication LAN CONFIG I
4. Keyboard Press a key to Figure 4 40 View the parameters for a GC device Enter setpoints View status information Use the keyboard and display to set all experimental parameters except flow rates The 6820 display and status board also provide feedback about GC performance before during and after a run Figure 4 shows the 6820 keyboard and a typical display Agilent 6820 GC Version A 01 02 Power on OK Stars Not Ready O Run o Kai Clock N 1a Tabie OVEN RAMP Ra te 7 Final Temp Initial Temp The GC keypad and display When first turned on the 6820 will run through routine self checks If the instrument passes these internal tests it will beep twice and display the message Power on OK 6820 Operation The Display 6820 Operation Controls and Components Think of the display as a window through which you view settings parameters and status information The top line is a title the other lines show content For long lists of items use the scroll keys to see the additional lines Showing all lines of infor
5. e You do not have the hardware on your instrument to support the operation you have requested Press Clear to remove the message You must enter a new setpoint change the hardware or reconfigure the instrument before continuing 6820 Operation 6820 Operation Controls and Components Popups Popups appear when a Shutdown Fault or Warning occurs They contain the type and number of the error and a brief description See your Agilent 6820 GC Maintenance and Troubleshooting manual on the 6820 User Information CD for details SHUTDOWN 1 Oven shut off ss Press Clear to remove the message 45 Controls and Components Status Indicators 46 Table 2 describes the status indicators STATUS Not Ready O Run O Clock Remote O Table OVEN RAMP Rate R Final Temp Pre Run O Initial Temp Table2 Status indicator LEDs LED Description Pre Run Lit when the GC is in the Pre Run state after pressing Prep Run See page 48 for more information Oven Ramp LEDs Show the progress of the oven temperature program The Rate LED blinks if the oven is unable to follow the program Not Ready Lit when the GC is not yet ready to make a run Blinks when the instrument has one or more fault conditions Press the Status key to see which parameters are not ready or what faults have occurred Run Lit when the instrument is executing a chromatographic run Remote Indicates that commun
6. Entering setpoints 68 To turn a device On Off 70 4 Setting the Operating Parameters Configure the Instrument 72 Set the time and date 72 Configure the oven 72 Configure the radix type 73 Configure the inlets 73 Configure the Aux thermal zones 74 Configure the valves 74 Configure the setpoint status list 75 Configure your RS 232 communications settings 76 6820 Operation Configure your LAN communications 77 Configure auto preprun 78 Setting the Column Oven Setpoints 79 Oven setpoints 79 Setting up an isothermal run 80 Setting up asingle ramp program 80 Setting up a multiple ramp program 81 Total run time 81 Setting the Inlet Parameters 82 Setting the Detector Parameters 84 Electron Capture Detector ECD 84 Flame lonization Detector FID 85 Thermal Conductivity Detector TCD 86 Nitrogen Phosphorus Detector NPD 88 Controlling the Valves 90 Controlling valves from the keyboard 90 Controlling valves from the run time tables 90 Valve control examples 91 Gas sampling valve 92 Setting Auxiliary Heated Zones 94 Generalcomments 94 Selecting Signal Output 95 Setting signals 95 Creating a column compensation profile 96 Making a run using column compensation 98 Plotting a stored column compensation profile 98 6820 Operation 11 12 5 Setting Flows About 6820 Flow Control 100 Tips 100 Maximum operating pressure 100 Where to Measure Flows 101 Detector and column flows 101 Inlet vent and septum purge flows 10
7. For less than 1 week 163 For more than 1 week 164 This section describes how to safely shut down the GC when not in use l 2 Agilent Technologies 161 Shutting Down Shutting Down the GC 162 CAUTION In general leave the GC power on when not in use This is a good idea because e Above ambient temperature plus carrier gas flow keep the column clean e Certain detectors may take some time to stabilize after they are turned off Leave the GC on between runs and overnight If you are using hydrogen gas you should turn off the hydrogen flow to avoid the possibility of an unmonitored leak when the GC is not in use for long periods To avoid damage to the column cool the oven before shutting off the carrier gas If using a TCD consider turning the filament off If the gas supply runs out while the GC is unattended the TCD filament can be damaged or destroyed Create Cerity Chemical shutdown methods Using Cerity Chemical create methods to facilitate GC shutdowns Create one method for preparing the GC for complete shutdown for example for service or storage and another method for conserving energy and supplies A conservation method should e Reduce detector inlet and oven temperatures to 150 200 C to save energy and preserve the column If using hydrogen carrier gas turn off the oven Turn off the TCD filament 6820 Operation 6820 Operation CAUTION Shutting Down A shutdown met
8. Method creation tips 152 Initial flow rates 152 Run Time Programming Using Run Time Events 153 To program run time events 155 To add events to the run table 156 To edit events inthe run table 156 To delete runtime events 157 Default Method Parameters 158 To load the default parameters 158 Method Mismatch 159 User entered configuration changes 159 Hardware configuration changes 160 Chapter 2 Strategy for Using the 6820 This section describes what a 6820 method is how methods are used by the 6820 and how to create them It then describes the advanced method features associated with the Run Table how to load default parameters for a method and how to interpret method mismatch errors l h Agilent Technologies 147 Developing Methods What is a Method A method is a collection of parameters required to run a single sample on the 6820 GC Methods make it possible to restore the instrument to a desired setup without reentering all the parameters Types of methods There are three kinds of methods The active method the settings that you are presently using Stored method one of the nine methods that can be stored in the GC The default method a set of default parameters for the GC It can be reloaded at any time The GC maintains the default method separately from the stored method How the GC uses the active method The GC keeps the active method separate from the stored methods This allows you to
9. Press Enter again to stop the stopwatch when the meniscus passes the 1 mL 10 mL or 100 mL line Calculate the flow rate in mL min from the 1 t value shown on the GC display If you used the 1 mL line the flow rate in mL min 1 t If you used the 10 mL line the flow rate in mL min 10 x 1 t If you used the 100 mL line the flow rate in mL min 100 x 1 t Press Clear to reset the stopwatch Repeat the measurement at least once to verify the flow 6820 Operation Related Topics Agilent 6820 Gas Chromatograph Operation 6 Running Samples Overview 134 Prepare the GC to Run Samples 135 Run a Sample Using Manual Injection 136 Run a Sample Using a Sampling Valve 138 Ignite the FID flame 140 Developing Methods Additional Information for Method Developers This section outlines the basic steps for using the 6820 Gas Chromatograph GC to acquire experimental data when you are not using Cerity Chemical or other Agilent data system It describes how to use some of the 6820 s features to best advantage and provides an operating framework that can be adapted to each user s needs EE Agilent Technologies Running Samples Overview There are three basic operating procedures for the 6820 when used in standalone mode e Prepare the GC to Run Samples on page 135 e Run a Sample Using Manual Injection on page 136 e Run a Sample Using a Sampling Valve on page 138 If your GC uses an inj
10. including flow rates for carrier and detector gases and temperatures 4 Perform the injection 5 Collect the data See Creating Methods on page 150 See Prepare the GC to Run Samples on page 135 Typically this is done by a Loading a stored collection of settings and instructions called a method then b Manually setting gas flows Alternately enter settings and instructions manually before each run See Run a Sample Using Manual Injection on page 136 and Runa Sample Using Manual Injection on page 136 Performed by the integrator or data system Creating Methods on page 150 gives an overview of the method creation process Chapter 6 Running Samples lists the basic procedures for operating the GC For more information about method creation and related topics see Chapter 8 Developing Methods 6820 Operation Agilent 6820 Gas Chromatograph Operation 3 Controls and Components GC Control and Component Locations 38 Keyboard and Display 40 The Display 41 Status Indicators 46 The Keyboard 47 Instant action keys Start Stop and Prep Run 48 Function keys 48 Short cut keys Temp and Ramp 49 Information keys 51 Miscellaneous keys 54 Modifier keys 61 Storage 63 How to Makea Setting 68 This section shows you where the controls are located on the 6820 and then describes how to use the electronic controls to perform a few common tasks Chap
11. or as a split peak There are two solutions to this problem e Use nitrogen or argon methane as carrier gas This eliminates problems inherent with using helium as carrier but causes reduced sensitivity to components other than hydrogen e Operate the detector at higher temperatures from 200 C to 300 C You can find the correct detector operating temperature by analyzing a known range of hydrogen concentrations increasing the operating temperature until the hydrogen peak exhibits normal shape and is always in the same direction negative relative to normal response to air or propane regardless of concentration This temperature also ensures high sensitivity and linear dynamic range See also Negative polarity on page 181 6820 Operation 181 Additional Information for Method Developers 182 Electron Capture Detector Safety precautions when handling ECDs Always observe the following precautions e Never eat drink or smoke when handling ECDs e Always wear safety glasses when working with or near open ECDs e Wear protective clothing such as laboratory jackets safety glasses and gloves and follow good laboratory practices Wash hands thoroughly with a mild non abrasive cleaner after handling ECDs e Cap the inlet and outlet fittings when the ECD is not in use Connect the ECD exhaust vent to a fume hood or vent it to the outside In the United States see the latest revision of Title 10 Code of
12. 25 Detector operating parameters Parameter Setpoint range Notes ECD Temp Output FID Temp Output TCD Temp Filament Output Neg polarity NPD Temp Output 0 400 C 0 425 C 0 400 C On Off On Off 0 400 C Detector temperature To keep the detector cell clean set this temperature higher than the oven temperature Display only Detector temperature To keep the detector cell clean set this temperature higher than the oven temperature Display only Detector temperature To keep the detector cell clean set this temperature higher than the oven temperature Display only Inverts detected peaks See Negative polarity on page 181 Detector temperature To keep the detector cell clean set this temperature higher than the oven temperature Display only 171 Additional Information for Method Developers Table 25 Detector operating parameters continued Parameter Setpoint range Notes Adjust offset 10 99 pA Suggested operating range is 30 to 40 pA Equib time 0 999 9 minutes Recommended is 0 0 minutes Default is 0 0 minutes Bead voltage 0 4 095 V Makeup gas flow Makeup gas enters the detector close to the end of the column Its purpose is to speed the peaks through the detector especially with capillary columns so that the peak separation achieved by the column is not lost through remixing in the detector
13. 3 3 3 Air 55 65 60 Column plus capillary makeup 5 10 Detector temperature 325 335 C is recommended Detector temperature should be greater than highest oven ramp temperature depending on the column type 188 6820 Operation Additional Information for Method Developers Gas pressures Choose a flow find a pressure and set source pressure 10 psi 70 kPa higher 150 7 Va Air 100 A Nn Flow a mL min d ie ra 2 50 P 5 Pa 3 Nitrogen Pa aT eer 0 aa Pressure psig 10 20 30 40 50 60 70 MPa 0 069 0 138 0 207 0 276 0 345 0 414 0 483 Flow mL min 0 Pressure psig 4 8 12 16 20 MPa 0 028 0 055 0 083 0 110 0 138 Figure 28 Pressure flow relationships for NPD 25 C 1 atmosphere 6820 Operation 189 Additional Information for Method Developers Valves 190 Types of valves The valve box The GC Fundamentals manual included on the 6820 GC User Information CD ROM contains details about how valves work The 6820 GC holds up to four valves in a heated valve box on top of the oven When installing valves using the Agilent valve box is preferred because it provides a stable temperature zone isolated from the column oven The 6820 supports two types of valves sampling and switching Of the four valves you can control only two can be configured as sampling valves gas or liquid If desired all val
14. Controlling the Valves 90 Setting Auxiliary Heated Zones 94 Selecting Signal Output 95 This section completely describes how to use the 6820 keyboard to make settings for all of the hardware you have installed It begins with the steps you need to take to set up configure your instrument for use and then describes how to use the inlets detectors the column oven and typical valves It also provides the procedures needed to set signal outputs Agilent Technologies 1 Setting the Operating Parameters Configure the Instrument Set the time an Configure the o 72 The instrument will need to be configured before the first use and whenever changing or adding new hardware Configuring the instrument sets global parameters such as date and time and also tells the instrument about the devices installed in it so that the GC can control them properly Typically configure the GC during installation and only modify the configuration as hardware changes Note that configuration settings directly affect your method Unconfigured devices may be unavailable on the display or may have no settable values Also these settings control the execution of certain tasks for example charging the sample loop of a gas sampling valve d date The GC has an internal clock and uses time and date for tasks such as logging methods and errors To set the time and date 1 Press Config 2 Scroll to the Time parameter then press Enter 3
15. ECD Aux gas Bottom AUX GAS ECD Anode purge Bottom ANODE PURGE FID Air Top AIR FID Hydrogen Middle HYDROGEN FID Aux gas External AUX GAS 110 6820 Operation Setting Flows Table 11 Controls for each gas flow for front ECD and back FID continued Gas flow Inlet type Set flow using this Module control pressure regulator Carrier gas Split Splitless External TOTAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only Table 12 Controls for each gas flow for front NPD and back FID Gas flow Inlet type Set flow using this Module control pressure regulator Front NPD air Top AIR Front NPD hydrogen Middle HYDROGEN Front NPD Aux gas Bottom AUX GAS Back FID air Top AIR Back FID hydrogen Middle HYDROGEN Back FID Aux gas Bottom AUX GAS Carrier gas Split Splitless External TOTAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only Table 13 Controls for each gas flow for two TCDs Gas flow Inlet type Set flow using this Module control pressure regulator Front TCD Aux gas Top AUX GAS Front TCD Reference Top REF Back TCD Aux gas Bottom AUX GAS Back TCD Reference Bottom REF 6820 Operation 111 Setting Flows Table 13 Controls for each gas flow for two TCDs continued Gas flow Inlet type Set flow using this Module control pressure regulator Carrier gas Split Splitless External TOTAL FLOW and CO
16. Many internal parts of the GC carry dangerous voltages 22 Electrostatic discharge is a threat to GC electronics 22 Many parts are dangerously hot 23 Hydrogen 24 Electron Capture Detector ECD 24 Safety and Regulatory Certifications 29 Symbols 30 Electromagnetic compatibility 31 Sound Emission Certification for Federal Republic of Germany 31 Cleaning 32 Recycling the Product 32 This section introduces several important terms discussed throughout this manual Also included in this section are Important Safety Warnings which list critical safety precautions for all users TE Agilent Technologies 17 Introduction Welcome 18 The Agilent Technologies 6820 Gas Chromatograph GC has many features designed to provide repeatable reliable operation These include e Automatic electronic control of operating temperatures e Control of analytical gas flows e Configurable signal output e Programmable oven temperature profile e Control of gas sampling switching and other valves e Configurable communications settings The 6820 automates most of these features so that once you determine the appropriate settings for an analysis you can recall those settings for use whenever needed In later sections this booklet will describe how to use these features to run samples for analysis First however we will define some common terms method lt A method on the 6820 is composed of all storable instrument settings After programm
17. Operation Setting Flows Table 19 Controls for each gas flow for front ECD and back NPD continued Gas flow Inlet type Set flow using this Module control pressure regulator Carrier gas Split Splitless External TOTAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only 6820 Operation 115 Setting Flows To Set the GC Flows Follow the steps below to set the flow rates for an analysis Setting the GC flow rates Step Notes 1 Verify that all appropriate inlet and liner hardware liner septum inserts and or adapter is installed 2 Verify that the appropriate column is installed 3 Verify the system is leak free 4 Verify gas supplies are sufficient for the analysis 5 Set the inlet flow rates See 6820 Flow Controls on page 104 To Set the Split Splitless Inlet Column and Split Vent Flows on page 117 To Set the Purged Packed Inlet Column Flow on page 121 6 Set the detector flow rates See 6820 Flow Controls on page 104 To Set FID Hydrogen Air and Aux Gas Flows on page 123 To Set the TCD Reference and Aux Gas Flows on page 125 To Set the ECD Aux and Anode Purge Gas Flows on page 127 To Set NPD Hydrogen Air and Aux Gas Flows on page 128 116 6820 Operation Setting Flows To Set the Split Splitless Inlet Column and Split Vent Flows 6820 Operation If using a split splitless
18. Set the inlet carrier gas flow before setting detector flows If you cannot obtain the inlet flow you need you may need to change the flow restrictor s in the flow module WARNING If setting flows at operating temperature the detector and exhaust gases may be hot enough to cause burns Wear heat resistant gloves when attaching and using the flow meter and adapters CAUTION If the carrier gas source runs out of gas or is turned off the column may be damaged if heated without carrier gas flow Maximum operating pressure The 6820 inlets and detectors are rated for carrier gas supply pressures up to 0 7 MPa 100 psi Operating the GC with higher pressures can cause leaks 100 6820 Operation Where to Measure Flows 6820 Operation Setting Flows Detector and column flows Measure all detector and column flows at the exit of the detector See Figure 9 If using an ECD the metal exhaust tube connects to a low pressure plastic vent tube on top of the oven Remove the metal exhaust tube from the rubber connector and insert it into the flow meter If using an NPD use a bubble meter with an NPD adapter part number G1534 60640 to measure flows Remove the bead and push the adapter into the collector You are now ready to measure the flow Quicker measurements can be made by measuring at the detector vent This measurement is 95 accurate when total flows exceed 50 mL min 101 Setting Flows ECD outlet t
19. Type Entries are automatically ordered chronologically when added 3 Select next event type 4 Set appropriate parameters Repeat this process until all other new entries are added To edit a clock time event 1 Press Clock Table to view all events programmed 2 Scroll to the event you want to change 3 Edit the time for an event move the cursor to the line labelled Time and type the desired time 4 Edit a value by scrolling to the item and pressing the On or Off key or enter a numerical value for the setpoint 6820 Operation 145 Scheduling Clock Time Events To delete a clock time event 1 Press Clock Table 2 Press the Delete key to remove an event from the clock time table Pressing the Delete key while in an existing time table produces the following display CLOCK TIME TABLE Delete this event ENTER to delete CLEAR to cancel 3 Press Enter to delete the current timed event press Clear to cancel this operation To delete the entire clock table To delete the entire table press Delete Clock Table The following display appears CLOCK TIME TABLE Delete entire table ENTER to delete CLEAR to cancel 146 6820 Operation Related topics Agilent 6820 Gas Chromatograph Operation 8 Developing Methods What is a Method 148 Types of methods 148 How the GC uses the active method 148 What Can You Do With It 149 Creating Methods 150
20. Use the Config key routinely to verify that the configuration is what you believe it to be Use the Info key for help with setpoint ranges next action to perform and other advice e Many settings require that you select from a list of choices The Mode Type key opens these lists If a setting seems to call for an entry other than a number or On or Off try Mode Type to see if there is an underlying menu Initial flow rates Refer to the Agilent Fundamentals of GC document part number G1176 90000 in English G1176 97000 in Chinese for information about starting column flow rates For information about initial flow rates for detectors see Selecting FID flow rates and temperature on page 174 Selecting TCD flow rates and temperature on page 179 Selecting ECD flow rates and temperatures on page 183 Selecting NPD flow rates and temperature on page 188 152 6820 Operation Developing Methods Run Time Programming Using Run Time Events 6820 Operation Run time programming allows certain settings to change automatically during a run as a function of the chromatographic run time Thus an event that is programmed to occur at 2 minutes will occur 2 minutes after every injection using that method You can program up to 25 run time events for a method At the end of the chromatographic run the GC automatically returns most settings changed by a run time table to their original values Valve event
21. by Agilent Technologies could void the user s authority to operate the equipment Sound Emission Certification for Federal Republic of Germany Sound pressure Sound pressure Lp lt 65 dB A according to DIN EN 27779 Schalldruckpegel Schalldruckpegel LP lt 65 dB A nach DIN EN 27779 6820 Operation 31 Introduction Cleaning Recycling the Product 32 To clean the unit disconnect the power and wipe down witha damp lint free cloth For recycling contact your local Agilent sales office 6820 Operation Related Topics Agilent 6820 Gas Chromatograph Operation 2 Strategy for Using the 6820 Overview 34 Storable experiment settings 34 Nonstorable experiment settings 35 Stored configuration settings 35 What is the difference between a 6820 method and a Cerity Chemical method for the 6820 35 Operating Strategy 36 Chapter 6 Running Samples Chapter 8 Developing Methods This section describes a helpful strategy for using the 6820 as a standalone instrument that outputs signal data to some device such as an Agilent 3396C integrator It also describes the types of settings the instrument stores and recalls Agilent Technologies 33 Strategy for Using the 6820 Overview This overview explains how some of the features of the 6820 interact during use and provides simplified procedures that can be adapted for your application Storable experiment settings The 6820 uses elec
22. d Enter values for the Time and Setpoint parameters Press Store and input a method number Set the temperature and run time If needed also program oven temperature ramps See Configure the oven on page 72 This can include temperature as well as other parameters such as inlet mode Choices depend on the analysis and the inlet type See Setting the Inlet Parameters on page 82 Set the temperature Enable the detector turn electrometer or filament on Set the detector data rate if available When using FID you must light the flame at run time See Setting the Detector Parameters on page 84 For example set the heated valve box temperature See Configure the Aux thermal zones on page 74 Signal parameters can include scaling factors and signal type See Signal Handling on page 198 If using a sampling or switching valve you can use the run table to control it Run Time Programming Using Run Time Events on page 153 for details about Run Table events 6820 Operation 151 Developing Methods Method creation tips When creating or modifying a method keep the following hints in mind e The available settings depend on what equipment is present While the GC can sense many of its components some information such as what type of inlet is installed must be entered by the user Always configure define instrument elements before trying to use them e
23. document or of any information contained herein Should Agilent and the user have a separate written agreement with warranty terms covering the material in this document that conflict with these terms the warranty terms in the sep arate agreement shall control Safety Notices CAUTION A CAUTION notice denotes a haz ard It calls attention to an operat ing procedure practice or the like that if not correctly performed or adhered to could result in damage to the product or loss of important data Do not proceed beyond a CAUTION notice until the indicated conditions are fully understood and met A WARNING notice denotes a hazard It calls attention to an operating procedure practice or the like that if not correctly per formed or adhered to could result in personal injury or death Do not proceed beyond a WARNING notice until the indicated condi tions are fully understood and met 6820 Operation Your 6820 User Information Products Available Learning Products Site Preparation and 6820 Operation Installation The learning products for the Agilent Technologies 6820 Gas Chromatograph GC consist of four manuals and a poster Use the poster as a guide during installation of your new instrument The four manuals are provided in a printable format on the CD ROM part number G1176 90005 included with the GC The easiest way to access the manuals on the CD is to insert it into a computer CD drive bro
24. during a run You will see higher relative noise at the faster sampling rates Doubling the data rate can double peak height while the relative noise increases by 40 Although noise increases the signal to noise ratio is better at the faster rates This benefit only occurs if the original rate was too low leading to peak broadening and reduced resolution We suggest that rates be chosen so that the product of data rate and peak width in seconds is about 10 to 20 Figure 33 shows the relationship between relative noise and data rates Noise decreases as the data rate decreases until you get to data rates of around 5 Hz As the sampling rate slows other factors such as thermal noise increase noise levels Excess noise due to flow oven temperature detector block temperatures etc Relative noise magnitude 200 100 50 20 10 5 2 1 0 50 0 20 0 10 Faster data rates Slower data rates Figure 33 Relationship of noise to data rates 6820 Operation 201 Additional Information for Method Developers Column compensation Peaks are integrated more accurately and repeatably on a flat baseline than on a rising baseline Column compensation corrects for baseline rise during temperature programming This is done by making a blank run one with no sample injected This run is stored and subtracted from the real run to produce a flat baseline Figure 34 illustrates the concept All conditions must be identical in the column compensat
25. during the run e Setting the signal level First we will discuss how to create a method Next we will discuss how to use run time events and how to revert to the default method Then we will describe what happens when a loaded method does not match current GC configuration 6820 Operation 149 Developing Methods Creating Methods Overview of creating a method To create a storable 6820 method first determine what settings you will need to enter and also what hardware inlet type liner type column carrier gas etc will be required to analyze the sample Once you know these you can create a 6820 method to store these conditions and configuration so they can be recalled and used whenever needed The procedure below lists all possible settings you may need to consider when creating a method The list of parameters for your instrument depends on the hardware installed in it For more information on what values to use see Chapter 10 Additional Information for Method Developers In most cases you can perform steps 2 through 9 in any order Always configure your instrument first so that the settings you need will be available Step Action Notes 1 Check instrument configuration a Install hardware if needed Verify correct hardware components b Configure the instrument if needed are installed See the Agilent 6820 GC Maintenance and Troubleshooting manual and Configure the Instrument on page 72 2 If usin
26. enter a new setpoint Equilibration time is not used when you enter a setpoint for Bead voltage so you cannot estimate your baseline stability Use the Bead voltage setpoint when the automatic startup does not work Bead voltage is also useful for small adjustments between runs If you observe a baseline drift you can enter a small one time change to compensate for the drift without having to wait for the Equib time Typical voltages for new beads range from 2 5 to 3 7 volts Higher values reduce bead life Extending the life of the bead Use the lowest practical Adjust offset or Bead voltage e Run clean samples e Turn the bead off when not in use e Keep the detector temperature high 820 to 335 C e Turn the hydrogen flow off during solvent peaks and between runs 187 Additional Information for Method Developers If your NPD is Off for a long time in a high humidity environment water may accumulate in your detector To evaporate this water 1 Set the detector temperature at 100 C and maintain it for 30 minutes 2 Set the detector temperature to 150 C and maintain it for another 30 minutes Selecting NPD flow rates and temperature Use the information in Table 31 when selecting temperatures and flows Table 31 Recommended temperature and flow rates NPD Gas Flow range Suggested flow mL min mL min Carrier gas Capillary columns 1 5 Detector gases Hydrogen 2 5
27. exchange WARNING Do not use solvents to clean the ECD You may not open the ECD cell unless authorized to do so by your local nuclear regulatory agency Do not disturb the four socket head bolts These hold the cell halves together Removing or disturbing them is a violation of the terms of the General License and could create a safety hazard 6820 Operation 27 Introduction 28 Safety precautions when handling ECDs Always observe the following precautions Never eat drink or smoke when handling ECDs Always wear safety glasses when working with or near open ECDs Wear protective clothing such as laboratory jackets safety glasses and gloves and follow good laboratory practices Wash hands thoroughly with a mild non abrasive cleaner after handling ECDs Cap the inlet and outlet fittings when the ECD is not in use Connect the ECD exhaust vent to a fume hood or vent it to the outside Agilent Technologies recommends a vent line inside diameter of 6 mm 1 4 inch or greater With a line of this diameter the length is not critical 6820 Operation Introduction Safety and Regulatory Certifications 6820 Operation Information The 6820 GC conforms to the following safety standards e Canadian Standards Association CSA C22 2 No 1010 1 e CSA Nationally Recognized Test Laboratory NRTL UL 61010A 1 e International Electrotechnical Commission IEC 61010 1 e EuroNorm EN 61010 1 The 6820 GC
28. for a sample It discusses requirements for GC gases the operation of the inlets important detector operational and usage details how signals are processed oven capabilities and how valves work 6820 Operation Contents 1 introduction Welcome 18 Where Dol Fitin 19 Important Safety Warnings 22 Many internal parts of the GC carry dangerous voltages 22 Electrostatic discharge is a threat to GC electronics 22 Many parts are dangerously hot 23 Hydrogen 24 Electron Capture Detector ECD 24 Safety and Regulatory Certifications 29 Information 29 Symbols 30 Electromagnetic compatibility 31 Sound Emission Certification for Federal Republic of Germany 31 Cleaning 32 Recycling the Product 32 2 Strategy for Using the 6820 Overview 34 Storable experiment settings 34 Nonstorable experiment settings 35 Stored configuration settings 35 What is the difference between a 6820 method and a Cerity Chemical method for the 6820 35 Operating Strategy 36 6820 Operation 3 Controls and Components GC Control and Component Locations 38 Keyboard and Display 40 The Display 41 Showing all lines of information 41 Symbols used inthe display 41 Sounds used with the display 43 Messages 44 Status Indicators 46 The Keyboard 47 Instant action keys Start Stop and Prep Run 48 Function keys 48 Short cut keys Temp and Ramp 49 Information keys 51 Miscellaneous keys 54 Modifier keys 61 Storage 63 How to Make a Setting 68
29. inlet in either mode you must set the column flow rate and the inlet vent flow rate In split mode the inlet vent flow is part of the split ratio The septum purge vent is not directly adjustable Pressure gauge for column head pressure TOTAL FLOW COLUMN HEAD PRESSURE INLET VENT VENT SPLIT SPLITLESS SEPTUM PURGE Figure 15 Split Splitless inlet module controls When performing splitless sampling and using hazardous chemicals and or H carrier gas connect effluent from the split vent and septum purge vent to a fume hood or appropriate chemical trap 117 Setting Flows 118 CAUTION To ensure proper operation make sure the carrier source pressure is at least 0 1 MPa 15 psi greater than the selected column head pressure If your instrument contains a TCD turn off the TCD filament before setting the flow rates Operating the TCD filament without carrier gas flow can damage the filament 1 Ifusing a TCD turn off the detector filament Press Front Det or Back Det scroll to Filament then press Off 2 Locate the knob labeled TOTAL FLOW Turn it clockwise as far as it will go Do not force the knob when it closes it comes to a slightly soft stop 3 Set the external source pressure regulator 0 07 to 0 14 MPa 10 to 20 psi higher than the pressure required on the GC internal regulator For example Does inlet use an internal regulator Pressure Yes No External regulator 0 55
30. of the GC carry dangerous voltages If the GC is connected to a power source even if the power switch is off potentially dangerous voltages exist on e The wiring between the GC power cord and the AC power supply the AC power supply itself and the wiring from the AC power supply to the power switch With the power switch on potentially dangerous voltages also exist on e All electronics boards in the instrument e The internal wires and cables connected to these boards e The wires for any heater oven detector inlet or valve box WARNING All these parts are shielded by covers With the covers in place it should be difficult to accidentally make contact with dangerous voltages Unless specifically instructed to never remove a cover unless the detector inlet or oven are turned off WARNING If the power cord insulation is frayed or worn the cord must be replaced Contact your Agilent service representative Electrostatic discharge is a threat to GC electronics The printed circuit PC boards in the GC can be damaged by electrostatic discharge Do not touch any of the boards unless it is absolutely necessary If you must handle them wear a grounded wrist strap and take other antistatic precautions Wear a grounded wrist strap any time you must remove the GC right side cover 22 6820 Operation Introduction Many parts are dangerously hot Many parts of the GC operate at temperatures high enough to caus
31. oven While programming the oven temperature Temp is the starting temperature setpoint Once the run begins the value of Temp changes with the oven program Changing Temp during a run causes an immediate change but the value is not saved to the next run Displayed only during a run Init Temp is set equal to Temp at the start of the run When the run ends the oven temperature is reset to the Init Temp value Therefore changing Init temp changes the starting temperature for the next run Time in minutes that the oven will stay at the starting temperature after a programmed run has begun The rate in C min at which the oven will be heated or cooled Temperature of the oven at the end of a heating or cooling rate Time in minutes that the oven will be held at the final temperature of a temperature programmed rate 6820 Operation 79 Setting the Operating Parameters Setting up an isothermal run An isothermal run is one in which the oven is maintained at a constant temperature To create an isothermal run set Rate 1 to Zero 1 Press Oven to access the oven parameter list OVEN Temp 30 Init time 30 lt 0 00 off 0 00 Rate 1 a 2 Enter the oven temperature for the isothermal run 3 Enter the number of minutes Init time that you want the 4 oven to stay at this temperature This time is the duration of the run If Rate 1 is not 0 enter zero for an
32. overwrites the configuration data in the method you are loading with the data from the active method METHOD MISMATCH ENTER to load default method CLEAR to cancel XM J Let s say for example you have a method for a split splitless inlet and a capillary column with a maximum oven temperature of 300 C Later you change the column to one that has a maximum temperature of 250 C and you configure the oven to have a maximum temp of 250 C If you try to load your existing method you will see a method mismatch Press Status to see which parameters are causing the method mismatch 159 Developing Methods STATUS Not Ready Oven max temp If you press enter the GC will keep the 250 C max oven temp The GC will not change the stored version of the method only the active method is changed If you want to keep the new configuration you must specifically store it Hardware configuration changes If the hardware has changed some parts of the method may be ignored You are warned if this happens For example suppose you replace the front FID with an ECD If you now load a method that uses the FID the FID parameters cannot load They will be ignored and current ECD parameters will be retained All other parameters that can be loaded will be loaded 160 6820 Operation Agilent 6820 Gas Chromatograph Operation 9 Shutting Down Create Cerity Chemical shutdown methods 162
33. run See Run Time Programming Using Run Time Events on page 153 for more information 91 Setting the Operating Parameters Gas sampling valve 92 Figure 8 shows a plumbing diagram for a single six port valve plumbed and configured as a gas sampling valve Gas and liquid sampling valves can start a run automatically when switched to the Inject position To column To column Carrier in Loop Load Inject position position Sampl am Sample in Sample Sample out lt out Load position the loop is flushed with a stream of the sample gas The column is flushed with carrier gas Inject position the filled loop is inserted into the carrier gas stream The sample is flushed onto the column The run starts automatically Figure 8 A gas sampling valve The sampling valve cycle is 1 The sampling valve rotates to the Load position Load time begins Valve is not ready 2 Load time ends The valve becomes ready 6820 Operation 6820 Operation Setting the Operating Parameters 3 If everything else is ready the GC becomes ready If everything else is not ready If you are using Clock Table the GC waits until everything is ready then executes the valve inject command If you are not using Clock Table the valve injection can be made at any time from the keyboard 4 The sampling valve rotates keyboard command to the Inject position Inject time begins The run begins 5 Inject time en
34. run Same as pressing prep run key at time event fires 142 6820 Operation 6820 Operation Scheduling Clock Time Events Table 20 Available clock time events continued Event Notes Col comp 1 Make a column comp run Col comp 2 Make a second column comp run Col comp 1 amp 2 Make two column comp runs Adjust offset Turns on at a specified time 143 Scheduling Clock Time Events Programming the Clock Table To program clock time events 1 Press Clock Table The following message will be displayed if no events are programmed CLOCK TIME TABLE Table empty Use Mode Type to select new entry JS 2 Press Mode Type to view the clock time program types CLOCK TABLE TYPE Load method lt Blank run Prep run Col comp 1 Col comp 2 Col comp 1 amp 2 3 Scroll to select the desired parameter and press Enter 144 6820 Operation Scheduling Clock Time Events CLK TBL 1 of 1 Time 10 00 lt 44 Clock time for event to occur Type Load method __ Event type for entry 1 Method 1 _________ Setpoint parameter varies with event type 4 Edit the Time and other setpoints for this event This allows you to program a specific time at which your GC will load a predetermined method To add an event to the clock table 1 Press Clock Table 2 To add new events to the clock table press Mode
35. see NOT include Run Table events for valve Run Time Programming Using control Run Time Events on page 153 a Press Valve Controlling the Valves on page 90 b Select the correct sampling valve then Valves on page 190 press On If using GC control and the method INCLUDES Run Table events for valve control Press Start 6820 Operation 139 Running Samples Ignite the FID flame To light the FID flame 1 Set the hydrogen and air flows See To Set FID Hydrogen Air and Aux Gas Flows on page 123 2 Turn the HYDROGEN and AIR flows on 3 Press Front Det or Back Det to see the detector output 4 Press FID IGNITOR on the FID module The signal typically increases to 5 to 20 pA after ignition Verify that the flame is lit by holding a cold shiny surface such as a mirror or chrome plated wrench over the collector exit Steady condensation indicates that the flame is lit If the flame does not light after several tries see your Agilent 6820 GC Maintenance and Troubleshooting manual on the 6820 User Information CD 140 6820 Operation Agilent 6820 Gas Chromatograph Operation 7 Scheduling Clock Time Events Overview 142 Types of clock table events 142 To program clock time events 144 To add an event to the clock table 145 To edit aclock time event 145 To delete a clock time event 146 To delete the entire clock table 146 Clock time events can be used to program certain
36. the ones associated with Pre Run Once these setpoints are ready the LED remains on and the purge valve switches to the inject position After a short 6 second equilibration time the instrument becomes ready for a run and the Not Ready light goes out If you press Prep Run while the Pre Run LED is blinking the purge valve immediately switches to the inject position before all the other setpoints are ready The Pre Run LED remains on Summary Table 3 lists the function keys a brief description of their use and where to find detailed information 6820 Operation Controls and Components Table3 The function keys Key Use to For more information Oven Aux 1 and Aux 2 Front Inlet and Back Inlet Front Det and Back Det Signal 1 and Signal 2 Col Comp 1 and Col Comp 2 Set oven temperatures both isothermal See Setting the Column Oven Setpoints on page 79 and temperature programmed Control extra temperature zones suchasa_ See Controlling the Valves on page 90 and Setting heated valve box or an unknown device Auxiliary Heated Zones on page 94 Can do temperature programming Control inlet operating parameters See Setting the Inlet Parameters on page 82 Control detector operating parameters See Flame lonization Detector FID on page 85 Electron Capture Detector ECD on page 84 or Thermal Conductivity Detector TCD on p
37. the other stop Controlling valves from the run time tables The Valve On and Valve Off commands can be run time programmed See Run Time Programming Using Run Time Events on page 153 and Programming the Clock Table on page 144 If a valve is rotated by a run time program it is not automatically returned to its initial position at the end of the run You must program this reset operation yourself 90 6820 Operation 6820 Operation Setting the Operating Parameters Valve control examples The two examples below explain the most common uses for valves These rotary valves have six ports and when the valve rotates it changes the flow of gases through the system This allows for tasks such as column switching and gas or liquid sampling To configure a valve see Configure the valves on page 74 A column selection valve Figure 7 shows a plumbing diagram for a single six port valve plumbed and configured as a switching valve Rotating the valve selects between one of two columns for analysis Front column Front column rh From inlet or To detector Back column ON OFF Figure 7 A column selection valve Select the column by pressing Valve scroll to the correct valve then press On for the front column or Off for the back column To ensure that the valve returns to the correct state after a run completes set a valve Off or On run time event to occur at the end of the
38. 20 Operation Setting the Operating Parameters If created separately the profiles are not dependent on the detector position For example you could create two profiles for the front detector each with different operating conditions If created simultaneously using the command Start comp 1 amp 2 profile 1 corresponds to detector 1 and profile 2 corresponds to detector 2 See the procedure below To create a column compensation profile 1 Set up the instrument for a run 2 Make a blank run to verify that the baseline is clean This is particularly important for new conditions or if the GC has been idle for several hours 3 Press Col Comp 1 or Col Comp 2 Message indicates status After a successful run it COLUMN COMP 1 says Data ok No data Press Front or Back key Detector Front to change the detector Start comp run Press Enter start the run and Start comp 1 amp 2 create one profile L Press Enter to start run and J create two profiles Col Comp 1 and Col Comp 2 4 Press Front or Back depending on the detector you are using 5 Select Start comp run or Start comp 1 amp 2 run Press Enter to start the run Start comp run creates one profile Start comp 1 amp 2 run creates two profiles using different detectors but the same oven temperature program 6 Ifthe run is successful the first line of the parameter list wi
39. 3 6820 Flow Controls 104 Flow and pressure controls 104 Single detector configurations 107 Two detector configurations 110 To Set the GC Flows 116 To Set the Split Splitless Inlet Column and Split Vent Flows 117 To set the column flow when using a valved injection 120 To Set the Purged Packed Inlet Column Flow 121 To Set FID Hydrogen Air and Aux Gas Flows 123 To Set the TCD Reference and Aux Gas Flows 125 To Set the ECD Aux and Anode Purge Gas Flows 127 To Set NPD Hydrogen Air and Aux Gas Flows 128 Adapters for Measuring Flow Rates 130 ECD TCD and NPD 130 FID 130 How to Measure Flow Rates Using a Bubble Meter 131 Measuring gas flows with a bubble meter 131 6820 Operation 6 Running Samples Overview 134 Prepare the GC to Run Samples 135 Run a Sample Using Manual Injection 136 Run a Sample Using a Sampling Valve 138 Ignite the FID flame 140 7 Scheduling Clock Time Events Overview 142 Clock table events and sample runs 142 Types of clock table events 142 Programming the Clock Table 144 To program clock time events 144 To add an event tothe clock table 145 To edit aclock time event 145 To delete a clock time event 146 To delete the entire clock table 146 8 Developing Methods What iis a Method 148 Types of methods 148 How the GC uses the active method 148 What Can You Do With It 149 Creating Methods 150 Method creation tips 152 Initial flow rates 152 Run Time Programming Using Run Time Events 153 T
40. 5 store digital 206 type 198 value 199 Signal n keys 49 single column compensation 202 Solvent peak NPD turning hydrogen off 186 split splitless inlet 167 flows setting 117 liners 167 parameters 82 start command 21 Status key 52 status table 52 Stop key 48 stopwatch 56 Store key 63 storing a method 64 Index T TCD See thermal conductivity detector Temp key 49 temperature auxiliary heated zone setpoint 94 ECD setpoint 84 FID setpoint 86 89 inlet setpoint 82 isothermal 80 oven maximum 73 programmed 196 TCD setpoint 87 temperature oven setpoint 79 test plot 204 thermal conductivity detector AUX GAS 125 carrier gas 178 flow and pressure 180 hydrogen analysis 181 makeup gas 178 negative polarity 181 REF gas flow rates 178 REF gas setting 125 setting flows 125 Time key 54 V value actual 43 setpoint 43 valve box 190 column selection 91 controlling 90 gas sampling parameters 92 heating configuration 191 Valve key 63 Z zero analog 203 211 Index 212 6820 Operation Eee Agilent Technologies Agilent Technologies Inc Printed in China April 2005 G1176 90014
41. ED 41000002015 Agilent 6820 Gas Chromatograph Operation Apg Agilent Technologies Notices Agilent Technologies Inc 2003 2004 2005 No part of this manual may be reproduced in any form or by any means including elec tronic storage and retrieval or translation into a foreign language without prior agree ment and written consent from Agilent Technologies Inc as governed by United States and international copyright laws Manual Part Number 61176 97014 Chinese 61176 90014 English Edition Second edition April 2005 First edition February 2004 Replaces part number G1176 90004 Printed in China Agilent Technologies Inc 412 Ying Lun Road Waigaoqiao Free Trade Zone Shanghai 200131 P R China Acknowledgements Microsoft Windows and Windows XP are registered trademarks of the Microsoft Corporation Warranty The material contained in this docu ment is provided as is and is sub ject to being changed without notice in future editions Further to the max imum extent permitted by applicable law Agilent disclaims all warranties either express or implied with regard to this manual and any information contained herein including but not limited to the implied warranties of merchantability and fitness for a par ticular purpose Agilent shall not be liable for errors or for incidental or consequential damages in connec tion with the furnishing use or per formance of this
42. Federal Regulations part 20 including appendix B or the applicable State regulation For other countries consult with the appropriate agency for equivalent requirements Agilent Technologies recommends a vent line inside diameter of 6 mm 1 4 inch or greater With a line of this diameter the length is not critical Linearity The ECD response factor versus concentration curve is linear for four orders of magnitude or more linear dynamic range 104 or higher for a broad range of compounds You should still run a calibration curve on your samples to find the limits of the linear range for your materials Detector gas The ECD operates with either nitrogen or argon methane as the makeup and anode purge gas Because of the high detector sensitivity carrier and makeup gas must be dry and oxygen free Moisture chemical and oxygen traps in good condition should be installed in carrier and makeup gas supply lines 6820 Operation 6820 Operation Additional Information for Method Developers Selecting ECD flow rates and temperatures To prevent peak tailing and to keep the cell clean the detector temperature should be set higher than the highest oven temperature used the setpoint should be based on the elution temperature of the last compound If you operate at excessively high temperatures your results will not necessarily improve and you may increase sample and column decomposition Use the information in Table 30 w
43. Flame lonization Detector The Flame Ionization Detector passes sample and carrier gas from the column through a hydrogen air flame The hydrogen air flame alone creates few ions but when an organic compound is burned there is an increase in ions produced A polarizing voltage attracts these ions to a collector located near the flame The current produced is proportional to the amount of sample being burned This current is sensed by an electrometer converted to digital form and sent to an output device Conditions for igniting the flame Before igniting the flame or if experiencing problems in lighting the flame check the following e Make sure the hydrogen and air gases are turned on and that the flow rates are high enough for the flame to ignite See Table 26 on page 174 172 6820 Operation 6820 Operation Additional Information for Method Developers Check that the right type of jet is installed for the column you are using Jet types are listed in the Agilent 6820 GC Maintenance and Troubleshooting manual on the 6820 User Information CD ROM Check for leaks Use an electronic leak detector to search for and correct leaks around the detector column fitting If the flame goes out also check the following Injecting large volumes of aromatic solvent can cause the flame to go out Switch to a nonaromatic solvent Check the column flow rate It may be too high Decrease the flow rate or pressure Switch to a more restrict
44. Inlet vent flow column flow 10 Repeat steps 8 and 9 until the flows are correct Excess carrier gas is vented through the SEPTUM PURGE VENT Although the septum purge vent is not adjustable check the flow to make sure it is working properly Do not cap off the flow from the purge vent 119 Setting Flows To set the column flow when using a valved injection The gas or liquid sampling valve is connected either e Directly onto the column e Into a split splitless inlet For valves connected directly to the column set the column flow using the regulator that supplies carrier gas to the valve For valves connected into a split splitless inlet set the inlet s column flow as shown in To Set the Split Splitless Inlet Column and Split Vent Flows on page 117 120 6820 Operation Setting Flows To Set the Purged Packed Inlet Column Flow If using a purged packed inlet you can only set the column flow rate The septum purge rate is not adjustable See Figure 16 Pressure gauge for column head pressure Me N g d p J CARRIER FLOW VENT SEPTUM PURGE Figure 16 Purged packed inlet flow controls To ensure proper operation make sure the carrier source pressure is at least 0 1 MPa 15 psi greater than the selected column head pressure CAUTION If your instrument contains a TCD turn off the TCD filament before setting the flow rates Operating the TCD filament without carrier gas flow can da
45. LUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW Table 14 Controls for each gas flow for two NPDs Gas flow Inlet type Set flow using this Module control pressure regulator Front NPD air Top AIR Front NPD hydrogen Middle HYDROGEN Front NPD Aux gas Bottom AUX GAS Back NPD air Top AIR Back NPD hydrogen Middle HYDROGEN Back NPD Aux gas Bottom AUX GAS Carrier gas Split Splitless External TOTAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only Table 15 Controls for each gas flow for front TCD and back FID Gas flow Inlet type Set flow using this Module control pressure regulator TCD Aux gas Bottom AUX GAS TCD Reference Bottom REF FID Air Top AIR FID Hydrogen Middle HYDROGEN FID Aux gas External AUX GAS 112 6820 Operation Setting Flows Table 15 Controls for each gas flow for front TCD and back FID continued Gas flow Inlet type Set flow using this Module control pressure regulator Carrier gas Split Splitless External TOTAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only Table 16 Controls for each gas flow for front TCD and back ECD Gas flow Inlet type Set flow using this Module control pressure regulator TCD Aux gas Top AUX GAS TCD Reference Top REF ECD Aux gas Bottom AUX GAS ECD Anode purge Bottom ANODE PURGE Carrier gas Split Splitless External TO
46. MPa 80 psi 0 41 MPa 60 psi pressure Internal regulator 0 41 MPa 60 psi pressure Maximum desired 0 28 MPa 40 psi 0 28 MPa 40 psi column pressure See 6820 Flow Controls on page 104 for details on regulator usage 4 If used set the internal 6820 carrier gas regulator pressure A typical starting value is 0 41 MPa 60 psi Carrier source pressure must be at least 0 1 MPa 15 psi greater than the maximum column head pressure 5 Set the oven temperature to the specified initial value Wait for the temperature to stabilize 6820 Operation 6820 Operation Setting Flows 6 Attach a flow meter to the detector outlet See Where to Measure Flows on page 101 There should be no flow at this time If there is turn the detector gas flows off 7 Turn the TOTAL FLOW knob in the lt INCR direction to turn the carrier gas flow on 8 Turn the COLUMN HEAD PRESSURE knob in the INCR gt direction The pressure will slowly rise Adjust and measure to achieve the desired column flow If you cannot increase TOTAL FLOW until you can Use TOTAL FLOW for coarse and COLUMN HEAD PRESSURE for fine adjustment 9 Move the flow meter to the SPLIT SPLITLESS INLET VENT Measure and adjust TOTAL FLOW to achieve the desired inlet vent flow Note that the head pressure reading will not change as you adjust the total flow rate If necessary increase the source pressure For split mode calculate the split ratio as
47. P address 000 000 000 000 lt Gateway 000 000 000 000 2 Scroll to Enable DHCP and press On The 6820 displays a message instructing the user to power cycle the instrument 3 Power cycle the 6820 4 Press Options Scroll to Communication and press Enter Confirm that Enable DHCP is On Configure auto prep run The 6820 can be set to automatically enter the pre run state To do this 1 Press the Config key to view a list of configurable parameters 2 Scroll to the Instrument parameter and press Enter 3 Scroll to Auto prep run and press On It is usually best to set Auto prep run to off This function applies only to the split splitless inlet in splitless mode and is equivalent to pressing Prep run See the GC Fundamentals book on your User Information CD ROM for information on the inlet modes If using Cerity Chemical Auto prep run must be set to off 78 6820 Operation Setting the Column Oven Setpoints Setting the Operating Parameters Press Oven and press On or Off to turn the oven on or off and to set the oven temperature profile You can also press Oven to see the current oven temperature and the current setpoint value Oven setpoints Table 8 describes the oven s programmable setpoints Table 8 Oven programming setpoints Setpoint During the run Temp Init temp Init time Rate Final temp Final time The current temperature setpoint for the
48. Run Log Press Run Log to display any deviations from the planned method including keyboard intervention during the most recent run Up to 50 run log entries can be stored and displayed The run log information can be used for local laboratory guidance standards such as GLP 6820 Operation Controls and Components Press Run Log r 4 gt RUN LOG Not ready Switching valve at time 0 00 Not ready Oven temp setpt at time 0 00 C IJ The run log is cleared at the start of a new run If no run deviations have been logged the following display is shown rg gt RUN LOG No deviations 6820 Operation 57 Controls and Components 58 Options Press Options to access the instrument setup options described in Table 4 Table 4 Instrument setup options Displayed option Use Service counter Calibration Communication Keybd amp Display Diagnostics Use these counters to track consumable part usage Calibrate your oven Set communication parameters for the instrument Customize keyboard behavior and set the radix type used by the GC For service personnel only Not for normal use Perform tests and set special conditions used to isolate problems Service counters The service counters track syringe septum and liner usage by counting each injection regardless of Front Back This provides a general guide on when to perfo
49. Scroll to the time and date lines and use the keypad to enter the current values ven Oven configuration sets the maximum temperature and equilibration time To configure the oven press Config then select Oven and press Enter Scroll to and enter e Maximum temp e Equib time Maximum temp Maximum allowable oven temperature setpoint Columns and some accessories such as the valves and the valve box have specific temperature limits When configuring Maximum temp consider these limits so that the 6820 Operation 6820 Operation Setting the Operating Parameters column and accessories are not damaged Oven setpoints are verified as they are entered a message is displayed when an entered setpoint is inconsistent with a previously defined maximum The Maximum temp setpoint can be 70 to 425 C Equib time The time required for the oven temperature to equilibrate at a new temperature setting Equilibration time begins when the actual oven temperature comes within 1 C of the oven temperature setting The Equib time setpoint can be 0 to 999 99 minutes The default time is 3 00 minutes Configure the radix type The 6820 GC is configurable for use with one of two radixes decimal separators the full stop and the comma Set the radix appropriate for your country 1 Press Options scroll to Keybd amp Display and press Enter The current radix setting is displayed 2 To change the radix type scroll to Rad
50. TAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only Table 17 Controls for each gas flow for front TCD and back NPD Gas flow Inlet type Set flow using this Module control pressure regulator TCD Aux gas Bottom AUX GAS TCD Reference Bottom REF NPD Air Top AIR NPD Hydrogen Middle HYDROGEN NPD Aux gas External AUX GAS 6820 Operation 113 Setting Flows Table 17 Controls for each gas flow for front TCD and back NPD continued Gas flow Inlet type Set flow using this Module control pressure regulator Carrier gas Split Splitless External TOTAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only Table 18 Controls for each gas flow for two ECDs Gas flow Inlet type Set flow using this Module control pressure regulator Front ECD Aux gas Top AUX GAS Front ECD Anode purge Top ANODE PURGE Back ECD Aux gas Bottom AUX GAS Back ECD Anode purge Bottom ANODE PURGE Carrier gas Split Splitless External TOTAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only Table 19 Controls for each gas flow for front ECD and back NPD Gas flow Inlet type Set flow using this Module control pressure regulator ECD Aux gas Bottom AUX GAS ECD Anode purge Bottom ANODE PURGE NPD Air Top AIR NPD Hydrogen Middle HYDROGEN NPD Aux gas Bottom AUX GAS 114 6820
51. age 86 or Nitrogen Phosphorus Detector NPD on page 88 Assign a signal usually to the front or See Selecting Signal Output on page 95 back detector Create and store a column compensation See Selecting Signal Output on page 95 profile 6820 Operation Short cut keys Temp and Ramp Use these keys to quickly access a setpoint from within a table Temp When not editing a list of parameters that contains a temperature setting for example from a Signal display or the Status display press Temp to jump to the first temperature setting of the oven profile If you are editing a list of parameters that contains a temperature setting for example the front detector press Temp to jump to that setting If the parameter is in the open list the cursor jumps to that line 49 Controls and Components 50 Ramp When not editing a list of parameters that contains a temperature ramp for example from a Signal display or the Status display press Ramp plus a number to display the Oven parameter list at the entered ramp If no ramps are specified the cursor is on the Rate 1 off line Press Ramp 2 7 OVEN Oven list opens Because Rate 1 off no temperature ramps are set on 0 00 lt this table the cursor is on the Rate 1 off line x A When editing an oven or an auxiliary zone parameters list press Ramp 1 5 to move the cursor to the firs
52. al This guide provides all supplemental information and procedures needed for everyday GC operation Read the Operation manual to learn e Important GC features How to use the controls to run samples e How the GC provides feedback to you about its performance e How to program analysis settings e How to program the 6820 to automate tasks e Where the GC controls are located and what they do How the GC components inlet detector column oven etc can impact your analysis e How to configure the GC when changing or modifying hardware How to safely shut down the GC when not in use e How to work safely when using the electron capture detector by using highly recommended safety precautions When you are ready to learn more about your instrument or if the instrument is in need of maintenance refer to the following manual as needed The information is arranged so that you can learn at your own pace reading only the information you need Maintenance and Troubleshooting This manual provides troubleshooting information and procedures and also step by step maintenance procedures It describes e What error messages mean and what to do about them e Chromatographic troubleshooting techniques 6820 Operation 6820 Operation How to replace consumable items such as inlet liners and septa How to perform simple performance enhancement procedures such as detector thermal cleaning How to diagnose and resolve certa
53. ame Description Detector output signals Front or back Front or back detector output Front comp 1 or Front comp 2 Front detector output minus column compensation profile 1 or 2 Back comp 1 or Back comp 2 Back detector output minus column compensation profile 1 or 2 Front back Front detector output minus back detector output 6820 Operation 6820 Operation Value Additional Information for Method Developers Table 35 6820 Signal choices continued Signal name Description Back front Back detector output minus front detector output Col comp 1 or Col comp 2 Column compensation profile 1 or 2 Nondetector output signals Test plot A test output See Test plot on page 204 Thermal Signals Select between temperature sensor readings for Diag Signals Diagnostic signals For use only by Agilent service representatives Avoid unless both detectors are of the same type When assigning detector signals use the Mode Type key and choose from the signal types listed or press a key or combination of keys Front Back Col Comp 1 and Col Comp 2 will work alone or in combination For example press Back for back detector or Back Front for back detector minus front detector Signal type can be programmed as a run time event See Run Time Programming Using Run Time Events on page 153 for details Value on the signal parameter list is the
54. arbon trap 200 cc HT200 2 Refill for HT200 2 ACR Molecular Sieve 5A GMSR For installation information see the 6820 Getting Started manual More about consumables and replacement parts For a wider selection of GC supplies as well as additional information refer to either the Agilent catalog for consumables and supplies or the Agilent web site at www agilent com chem 208 6820 Operation Index A actual value 43 adapters for measuring flows 130 AIR FID 124 129 analog output range 203 analog zero 203 ANODE PURGE gas ECD 127 asterisk in GC display 41 Aux keys 49 AUX GAS ECD 127 AUX GAS FID 124 129 AUX GAS TCD 125 Back Det key 49 Back Inlet key 49 Bead NPD 184 voltage 187 beep 43 59 bubble flow meter 131 C calibration option 59 caution message 44 Cerity Chemical methods conservation 162 methods shutdown 162 Clear key 62 click key 59 Clock Table key 63 LED 46 clock time adding events 145 deleting events 146 editing events 145 programming 144 145 Col Comp n keys 49 6820 Operation column compensation 202 compensation profile 96 compensation making arun 98 command start 21 communications option 59 compensation column 202 creating a profile 96 plotting a profile 98 Config key 59 configuration instrument 59 oven 72 setpoint status table 75 cursor 41 D data rate fast peaks 95 data system definition 18 default m
55. as necessary to obtain the correct total flow column makeup 5 Set the REF gas flow to be at least three times the total flow rate from the column plus makeup Therefore if the column 125 Setting Flows plus the makeup flow is 5 mL min the REF flow should equal 15 mL min a Open the on off valve for the REF gas b Use a small screwdriver to turn the variable restrictor at the center of the reference gas on off valve as necessary to obtain the correct flow If you cannot achieve the desired flow using the variable restrictor re adjust the supply pressure 126 6820 Operation Setting Flows To Set the ECD Aux and Anode Purge Gas Flows If using an ECD set the AUX GAS makeup and ANODE PURGE gas flows Refer also to Figure 19 On Off ANODE PURGE Figure 19 ECD flow controls Attach a flow meter to the outlet of the detector See Where to Measure Flows on page 101 for details 1 If you are using packed columns turn the AUX GAS off 2 If you are using capillary columns set the AUX GAS flow a Open the on off valve for the AUX GAS makeup and ANODE GAS and adjust the gas pressure to obtain the correct total flow b Set the ECD gas supply pressure to about 0 28 MPa 40 psi Wait for stabilization and measure flow 3 Open the on off valve for the ANODE PURGE gas 6820 Operation 127 Setting Flows To Set NPD Hydrogen Air and Aux Gas Flows WARNING Hydrogen and air form a flammabl
56. ccur Type B det polar Event type for entry 1 Setpoint On Setpoint parameter varies with event type ei The programmed events are arranged in order of execution time To add events to the run table 1 To add new events to the run table press Mode Type while on the Time or Type line of any entry 2 Select the event type 3 Set appropriate Time and Setpoint parameters Repeat until all entries are added Events are automatically placed in order by execution time To edit events in the run table 1 Press Run Table 2 Move the cursor to the event you want to change 3 To edit the time for an event move the cursor to the line labeled Time Type the desired time and press Enter 4 To edit a value scroll to the item and press the On or Off key or enter a numeric value for the setting Press Enter 156 6820 Operation 6820 Operation Developing Methods To delete run time events 1 Press Run Table to access the run time table 2 From within this table press the Delete key to delete the current event from the run time table Pressing Delete while in an existing time event table produces the following display RUN TIME TABLE Delete this event ENTER to delete CLEAR to cancel I 3 Press Enter to delete the current timed event press Clear to cancel this operation 157 Developing Methods Default Method Parameters The GC software s
57. change test or use method settings without losing stored information When you turn the instrument off the GC saves the active method and reloads it automatically when you turn the instrument back on However if the hardware is changed while the instrument is turned off it may not be possible to restore all parameters in the method resulting in an error condition When you load a stored method that stored method becomes the active method It replaces whatever settings had been in use 148 6820 Operation Developing Methods What Can You Do With It Methods can be created loaded stored modified and deleted The GC can store up to nine 9 user defined methods e To load store or delete a method see The method keys Load Store and Method on page 64 e To create a method modify the active method with the new parameters then store the method as one of the nine stored methods See Creating Methods on page 150 e To modify a method 1 Load it 2 Make the desired changes to the settings 3 Store it to the same method number In addition to basic instrument control of temperatures and run times the method can also perform run time events Run time events are functions or settings programmed to occur at a specified time during the run They may include e Modifying the signal sent to the data collection device or computer e Determining or changing the signal type e Switching rotating valves
58. columns set the AUX GAS flow a b c Make sure the AIR and HYDROGEN flows are turned off Open the on off valve for the AUX GAS makeup Set the supply pressure for the AUX GAS to about 0 28 MPa 40 psi Use a small screwdriver to turn the variable restrictor at the center of the FID AUX GAS knob as necessary to obtain the correct total flow column makeup If you cannot achieve the desired flow using the variable restrictor re adjust the supply pressure 6820 Operation Setting Flows To Set the TCD Reference and Aux Gas Flows 6820 Operation CAUTION If using a TCD set the REF reference gas and AUX GAS makeup flows Refer also to Figure 18 On Off and adjustment AUX GAS Figure 18 TCD flow controls Turn the TCD filament off before setting the flow rates Operating the TCD filament without carrier gas flow can damage the filament 1 Turn off the detector filament Press Front Det or Back Det scroll to Filament then press Off 2 Attach a flow meter to the outlet of the detector See Where to Measure Flows on page 101 for details 3 Ifyou are using packed columns and are not using the makeup gas turn AUX GAS off and proceed to step 5 4 Set the makeup flow as follows a Open the on off valve for the AUX GAS makeup b Set the TCD gas supply pressure to about 0 28 MPa 40 psi c Use a small screwdriver to turn the variable restrictor at the center of the TCD AUX GAS knob
59. conforms to the following regulations on Electromagnetic Compatibility EMC and Radio Frequency Interference RFI e CISPR 11 EN 55011 Group 1 Class A e IEC EN 61326 e AUS NZ This ISM device complies with Canadian ICES 001 Cet appareil ISM est conforme a la norme NMB 001 du Canada The 6820 GC is designed and manufactured under a quality system registered to ISO 9001 The Agilent Technologies 6820 Gas Chromatograph meets the following IEC International Electro technical Commission classifications Safety Class I Transient Overvoltage Category II Pollution Degree 2 This unit has been designed and tested in accordance with recognized safety standards and is designed for use indoors If the instrument is used in a manner not specified by the manufacturer the protection provided by the instrument may be impaired Whenever the safety protection of the 6820 Gas Chromatograph has been compromised disconnect the unit from all power sources and secure the unit against unintended operation 29 Introduction Refer servicing to qualified service personnel Substituting parts or performing any unauthorized modification to the instrument may result in a safety hazard Symbols Warnings in the manual or on the instrument must be observed during all phases of operation service and repair of this instrument Failure to comply with these precautions violates safety standards of design and the intended use of the instrument A
60. d 1 Press Method to access the STORED METHODS listing 2 Scroll to the method you wish to load STORED METHODS 1 9 49 10 Jun 03 lt 2 lt empty gt 3 lt empty gt 4 lt empty gt 5 lt empty gt 65 Controls and Components 3 Press the Load key You are prompted to either load the method by pressing Enter or to cancel this function by pressing Clear 4 Press Enter to load the method The selected method replaces the active method LOAD METHOD Meth 1 loaded J Clear exits this function and returns to the STORED METHODS listing To load the default method The GC default parameters can be reloaded at any time 1 Press Method 2 Scroll to Default method STORED METHODS 2 lt empty gt 3 9 57 10 Jun 03 4 lt empty gt 5 lt empty gt Default method lt OEE A J 66 6820 Operation 6820 Operation Controls and Components 3 Press Enter 4 Press Enter when prompted to load the default method To modify a previously stored method When a method is loaded it replaces the active method You can modify a previously stored method by 1 Loading the desired method 2 Making the appropriate changes 3 Storing this method under the same method number overwrite the original method or store as a different method number To delete a stored method 1 Press Method scroll to the approp
61. d frequently Carrier reference and makeup gas The reference and the makeup gas are the same as the carrier gas Reference gas flow Use Figure 26 to select a value for reference gas flow for either capillary or packed columns Any ratio within 0 25 of that in the figure is suitable 4 0 z 35 zs a 3 0 Sa c 2 5 SE x B 1 5 HE ES 1 0 2 e 0 5 0 t T T T T t 10 20 30 40 50 60 Column makeup flow mL min Figure 26 Selecting the reference gas flow Makeup gas When using packed columns we recommend a small makeup gas flow 2 to 3 mL min to get the best peak shapes 178 6820 Operation 6820 Operation Additional Information for Method Developers Selecting TCD flow rates and temperature Use the information in Table 29 when selecting temperatures and flows for the TCD Table 29 Recommended flow rates and temperatures Gas type Flow range Carrier gas Packed 10 to 60 mL min hydrogen helium nitrogen Capillary 1 to 5 mL min Reference 15 to 60 mL min same gas type as carrier See Figure 27 to select a value Capillary makeup 5 to 15 mL min capillary columns same gas type as carrier 2 to 3 mL min packed columns Detector temperature lt 150 C cannot turn on filament Detector temperature should be 30 C to 50 C greater than highest oven ramp temperature Gas pressures Use Figure 27 to locate minimum source pressures Set source tank pressur
62. ditional Information for Method Developers Split Splitless inlet Operating modes The split splitless inlet has two operating modes split and splitless Split The sample is divided between the column and a vent flow The split mode is generally used for major component analyses and for high concentration samples when you can afford to lose most of the sample out the inlet vent It is also used for samples that cannot be diluted Splitless The sample is not divided during the initial part of the injection Most of it enters the column A small amount is purged from the inlet to avoid excessive peak broadening and solvent tailing At a specified time determined by the purge time parameter in the method the inlet s purge valve opens and excess mostly solvent vapors are swept out the inlet vent while carrier gas maintains flow through the column The splitless mode is generally used for trace analyses When developing a splitless injection method adjust the purge time parameter to maximize sample response while eliminating as much of the solvent peak as possible Liners Choose liners according to the type of injection you are doing split or splitless To choose the proper liner for a specific application consider e Liner volume e Liner treatments or deactivation to reduce sample degradation e Any liner design features that might affect carrier gas flow through the inlet or sample vaporization For more information o
63. ds Return to step 1 See also Run a Sample Using a Sampling Valve on page 138 93 Setting the Operating Parameters Setting Auxiliary Heated Zones General comments If available use the auxiliary heated zone to control the temperature of an installed accessory The most common device is a valve box To set the temperature of the heated zone 1 Press Aux and input the number of the zone 1 or 2 2 Input the temperature and press Enter 94 6820 Operation Selecting Signal Output Setting signals 6820 Operation Setting the Operating Parameters Use the Signal 1 and Signal 2 keys to set up and assign the output from the GC The setup can include the signal type analog data rate if using an analog device and column compensation profile s Note that if you are using only a digital data system such as Cerity Chemical you do not need to set the analog data rate Type To set up a signal first select the type of data to be sent to the data collection device 1 Press Signal 1 or Signal 2 2 Scroll to Type and press Mode Type In the list presented scroll to the appropriate signal output and press Enter to select it In general set Signal 1 to use the output from the front detector and front inlet and column1 Set Signal 2 to use the output from the back detector 3 If using analog output scroll to Zero and either enter the offset value from 500000 to 500000 or press On to se
64. e Back Detector installed equipment Signal 1 Signal 2 Aux Me A 6820 Operation Controls and Components Modifier keys Modifier keys extend the functions of some setpoint control keys Mode Type Press Mode Type to access the list of possible settings or types for a non numeric setpoint that is inlet type To change a mode or type scroll to the desired line and press Enter An asterisk marks the current mode or type The following are examples of Mode Type functions Example Mode selection for a split splitless inlet 1 Press Front Inlet 2 Press Mode Type p gt M F INLET S SL F INLET MODE Mode em am Split Temp Splitless lt 24 250 Purge 1 20 q D j y J Example Type selection for Signal 1 1 Press Signal 1 2 Press Mode Type SIGNAL 1 SIGNAL 1 TYPE Type Back lt Front Value Bl pack lt 0 0 Front comp 1 Zero Front comp 2 0 0 Back comp 1 Range 0 Back comp 2 es 6820 Operation 61 Controls and Components Clear Press Clear to e Clear mis entered setpoints only available before pressing Enter while the is still flashing e Back out of the Mode Type selection list before pressing Enter e Return to an upper level in nested parameter lists such as Config or Option lists e Clear the stopwatch to zero Clear an Info message and return t
65. e at least 70 kPa 10 psi or higher than the pressure used 179 Additional Information for Method Developers 70 50 Reference gas flow mL min 30 20 10 0 Pressure kPa 69 138 207 276 345 414 psi 10 20 30 40 50 60 20 18 16 14 12 Makeup gas flow 10 we j Helium mL min 9 f 7 Hydrogen Nitrogen Pressure kPa 69 138 207 276 345 414 psi 10 20 30 40 50 60 Figure 27 Typical pressure flow relationships reference and makeup gases at 25 C and 1 atmosphere pressure 180 6820 Operation Additional Information for Method Developers Negative polarity Sample components with higher thermal conductivities than the carrier gas produce negative peaks For example helium or hydrogen form a negative peak with nitrogen or argon methane as the carrier gas Neg polarity ON inverts the peak so the integrator or Agilent data system Cerity Chemical can measure it You can set Neg polarity as a run time event See Run Time Programming Using Run Time Events on page 153 Analyzing for hydrogen Hydrogen is the only element with thermal conductivity greater than helium and mixtures of small amounts of hydrogen lt 20 in helium at moderate temperatures exhibit thermal conductivities less than either component alone If you are analyzing for hydrogen with helium carrier gas a hydrogen peak may appear as positive negative
66. e mixture Do not set the hydrogen flow with air flow on Do not set the air flow with the hydrogen flow turned on If using an NPD set the hydrogen fuel air and Aux gas makeup flows as described in Figure 20 On Off On Off On Off and adjustment Figure 20 NPD flow controls 1 Attach a flow meter to the outlet of the detector See Where to Measure Flows on page 101 for details 2 Adjust the hydrogen flow a Turn off the AIR and AUX gases b Open the on off valve for HYDROGEN c Set the supply pressure wait for stabilization and measure the flow d Repeat 2c until the HYDROGEN flow is correct If you have flow through your column be sure to subtract it from the total flow e Close the on off valve for HYDROGEN flow while you measure AIR flow 128 6820 Operation 6820 Operation Setting Flows Adjust the AIR flow a Make sure the HYDROGEN and AUX GAS flows are turned off b Open the on off valve for AIR c Set the supply pressure wait for stabilization and measure flow d Repeat step 3c until the AIR flow is correct If you have flow through your column subtract it from the total flow e Close the on off valve for AIR If you are using packed columns turn the AUX GAS off If you are using capillary columns set the AUX GAS flow a Make sure the AIR and HYDROGEN flows are turned off b Open the on off valve for the AUX GAS makeup c Set the supply pressure for the AUX GAS to abou
67. e serious burns These parts include but are not limited to e The inlets e The oven and its contents e The detectors e The column nuts attaching the column to an inlet or detector e The valve box You should always cool these areas of the GC to room temperature before working on them They will cool faster if you first set the temperature of the heated zone to room temperature Turn the zone off after it has reached the setpoint If you must perform maintenance on hot parts use a wrench and wear gloves Whenever possible cool the part of the instrument that you will be maintaining before you begin working on it WARNING Be careful when working behind the instrument During cool down cycles the GC emits hot exhaust which can cause burns WARNING The insulation around the inlets detectors valve box and the insulation cups is made of refractory ceramic fibers To avoid inhaling fiber particles we recommend the following safety procedures ventilate your work area wear long sleeves gloves safety glasses and a disposable dust mist respirator dispose of insulation in a sealed plastic bag wash your hands with mild soap and cold water after handling the insulation 6820 Operation 23 Introduction 24 Hydrogen Hydrogen gas may be used as carrier gas and or as fuel for the FID When mixed with air hydrogen can form explosive mixtures When using hydrogen H as the carrier gas or fuel gas be aware tha
68. ection technique other than either manual syringe injection or sampling valve injection refer to the operating information that came with your hardware for information about how the above procedures should be adapted 134 6820 Operation Running Samples Prepare the GC to Run Samples 6820 Operation This procedure applies regardless of your data collection device for example Cerity software or an integrator or sample introduction technique Always perform this procedure before running samples To prepare the GC to run samples Step Notes 1 Check gas supplies and source Insure the supply is adequate for all pressures sample runs 2 Check the power supply Restore power if interrupted 3 Turn onthe GC If installed also turn See the Cerity Chemical online help on any computer or communication or your integrator s supplied systems and start any required instruction manual software 4 If needed install new inlet and e Liner detector hardware Septum Adapter e Other hardware refer to the section for each inlet detector 5 Check the identity of the installed If needed change the column See column s your Agilent 6820 GC Maintenance and Troubleshooting manual 6 Check for leaks See your Agilent 6820 GC Maintenance and Troubleshooting manual 7 Check the availability of the samples to be analyzed 8 Confirm what method is required 135 Running Samples Run a Sample Using Manual Injectio
69. ector configurations 110 To Set the GC Flows 116 To Set the Split Splitless Inlet Column and Split Vent Flows 117 To Set the Purged Packed Inlet Column Flow 121 To Set FID Hydrogen Air and Aux Gas Flows 123 To Set the TCD Reference and Aux Gas Flows 125 To Set the ECD Aux and Anode Purge Gas Flows 127 To Set NPD Hydrogen Air and Aux Gas Flows 128 Adapters for Measuring Flow Rates 130 How to Measure Flow Rates Using a Bubble Meter 131 Measuring gas flows with a bubble meter 131 This section describes how to set the gas flows used in the 6820 It also describes how to measure flows using a typical bubble flow meter and the instrument s internal stopwatch l i Agilent Technologies 99 Setting Flows About 6820 Flow Control This section describes how to set the various flow rates in your instrument Tips When setting flow rates please keep the following tips in mind The instructions recommend starting pressures and flows Adjust the source pressures as needed for your analysis You can set the flow rates with all GC components inlet column oven detector at either ambient temperature or at an appropriate operating temperature To achieve the most repeatable results always use the same technique If setting flows at an elevated temperature be sure to keep carrier gas flowing through the column at all times To set flows at an elevated temperature first download the appropriate Cerity Chemical method to the GC
70. eeps Method mod beep turn ON for high pitched beep when method setpoint is modified e Radix type allows you to choose between a period or comma Config Press Config to set up configurations for instrument control Most configuration settings either do not change frequently or apply to every run Some examples are date and time maximum oven temperature inlet type and gas sampling valve loop size 59 Controls and Components 60 If you press Config the GC displays a list of configurable items You can either Scroll to the item and press Enter to select it or e Press a function key for example Front Det or either Time or Status to configure that item For example to configure the oven you can either e Press Config scroll to Oven and press Enter or Press Config Oven Configure a detector for use or maintenance For detectors that use an electrometer the FID and ECD you can turn the electrometer off before performing repairs Normally leave the electrometer on To enable or disable a detector 1 Press Config Front Det or Config Back Det 2 Scroll to Electrometer and press On or Off Press the Config key to obtain a listing of configurable parameters a k CONFIG Scroll to the Instrument Oven parameter Press Enter to access the Config Instrument settings Front Detector lt list Types shown depend on th
71. eflects the speed of the gas through the tube Most bubble flow meters have sections of different diameters so they can measure a wide range of flows conveniently A bubble flow meter with marks at 1 10 and 100 mL is suitable for measuring both low flow rates such as carrier gases and higher flow rates such as air for an FID See Figure 23 10 mL line 100 mL line Gas inlet Figure 23 A three volume bubble meter 6820 Operation Measuring gas flows with a bubble meter Tools e Bubble meter graduated at 1 10 and 100 mL Bulb half filled with soapy water e Adapter for detector or vent as needed See Adapters for Measuring Flow Rates on page 130 e GC internal stopwatch 131 Setting Flows 132 Do not measure hydrogen together with air or oxygen This can create explosive mixtures that may be ignited accidentally Always measure gases separately Attach the gas inlet line of the bubble meter to the fitting where you will measure flow Use the appropriate adapter if needed Start the flow before connecting the bubble meter Hold the bubble flow meter vertically squeeze and release the bulb to create a meniscus in the bubble meter Do this several times to wet the sides before taking measurements Press Time to see the stopwatch screen Squeeze the bulb Press Enter to start the stopwatch when the meniscus passes the START lowest line in the bubble flow meter
72. election 167 modes 167 setting flows 117 inlets overview 166 IP address 77 isothermal oven 80 K key click 59 keyboard 47 lock 59 L LAN communications 77 linearity ECD 182 liners split splitless inlet choosing 167 Load key 63 loading default method 66 default parameters 158 lock keyboard 59 210 M makeup gas definition 172 messages 44 meter flow measuring 131 method definition 148 deleting 67 editing 67 loading default 66 mismatch 159 storing 64 Method key 63 method definition 18 methods Cerity Chemical conservation 162 shutdown 162 Mode Type key 61 Nitrogen phosphorus detector adjust offset 184 aborting 185 bead 184 voltage 187 electrometer 88 equilibration time 88 hydrogen off 186 solvent peak turning hydrogen off 186 turning off 186 Not Ready LED 46 0 Options key 58 output analog 203 definition 198 digital rates available 200 signal type 198 oven configuration 72 equilibration time 73 fast rates 197 isothermal 80 maximum temperature 73 safety 195 specifications 194 temperatures setting 79 Oven key 49 P parameters default 158 inlet 167 polarity TCD 181 Pre Run LED 46 Prep Run key 48 procedure adding events clock table 145 run table 156 auto prep run 78 configuring setpoint status table 75 valves 74 controlling valves from the keyboard 90 creating a column compensation profile 96 de
73. emperature allowed for the column because part of the column passes through the TCD heated block and into the cell See To Set the Split Splitless Inlet Column and Split Vent Flows on page 117 or To Set the Purged Packed Inlet Column Flow on page 121 See To Set the TCD Reference and Aux Gas Flows on page 125 See How to Make a Setting on page 68 Allow about 30 minutes for thermal stabilization before using A longer period may be required for the highest sensitivity See How to Make a Setting on page 68 and Negative polarity on page 181 When a sample contains components giving both positive and negative going peaks Neg polarity can be switched on and off during arun as a timetable event CAUTION Never turn the filament on without a normal column flow through the detector If the flow is off the filament will overheat and break Always turn the filament off before servicing the detector 6820 Operation 87 Setting the Operating Parameters Nitrogen Phosphorus Detector NPD CAUTION Electrometer The Configure Detector parameter list contains an On Off setpoint for the Electrometer You do not need to turn the electrometer on and off when operating your NPD Do not turn off the electrometer during a run It will turn off the detector Output Equilibration time The Configure Detector parameter list contains a setpoint for Equib time Equilibratio
74. erating See How to Make a Setting on temperature and turn it on page 68 6820 Operation 6820 Operation Setting the Operating Parameters To use the ECD continued Step Notes 4 Set the inlet column flow rates 5 Set the detector makeup gas flow rate 6 Turn the detector electrometer on See To Set the Split Splitless Inlet Column and Split Vent Flows on page 117 or To Set the Purged Packed Inlet Column Flow on page 121 See To Set the ECD Aux and Anode Purge Gas Flows on page 127 See How to Make a Setting on page 68 Flame lonization Detector FID CAUTION Electrometer The Configure Detector parameter list contains an On Off setting for the Electrometer You do not need to turn the electrometer on and off when operating your FID The only time you need to turn off the electrometer is when cleaning the detector Do not turn off the electrometer during a run It will cancel detector output To use the FID Step Notes 1 Install the correct column adapter 2 Install the column and check for leaks See the Agilent 6820 GC Maintenance and Troubleshooting manual See the Agilent 6820 GC Maintenance and Troubleshooting manual 85 Setting the Operating Parameters To use the FID continued Step Notes Set the detector operating temperature and turn it on Set the inlet column flow rates Set the detector ma
75. ethod 66 default parameters 158 Delete key 62 deleting a method 67 detector overview 170 detectors setting parameters 84 DHCP for IP addressing 78 diagnostics option 59 display 41 blinking 42 LED 46 E ECD See electron capture detector editing a method 67 Electrometer NPD 88 electrometer ECD 84 FID 85 electron capture detector ANODE PURGE gas 127 AUX GAS 127 gases 182 linearity 182 safety 28 182 setting flows 127 Equilibration time NPD 88 equilibration time oven 73 errors 44 F fast peaks 96 FID See flame ionization detector final temp LED 46 oven 79 final time oven 79 flame ionization detector 172 AIR flow 124 129 AUX GAS 124 129 data rates 95 electrometer 84 85 fast peaks 96 HYDROGEN gas 123 128 pressure and flow 175 setting flows 123 128 Flow key 49 flow rates adapters for 130 flow measuring meter 131 flows setting 116 ECD 127 FID 123 purged packed inlet 121 split splitless inlet 117 TCD 125 Front Det key 49 Front Inlet key 49 209 Index G gas purity and ECD performance 182 gas sampling valve 92 gas hydrogen safety 162 gas makeup definition 172 Hydrogen NPD turning off during solvent peak 186 hydrogen analysis for 181 flow FID 123 128 Info key 51 Init Temp oven 79 Initial Temp LED 46 inlet purged packed flow ranges 168 setting flows 121 source pressures 168 inlet split splitless liner s
76. ets flows Sets temperatures Injects sample 6820 provides output to the integrator Presses start button Figure 1 Process for running a sample when using manual injection and an integrator for data collection You can see from Figure 1 that the operator Enters all of the instrument settings e Makes the sample injection e Presses start 20 6820 Operation Introduction oy Cerity Chemical initially Analysi It eo nalysis results provides gt amp Temperature settings Cerity Chemical provides S an B the final results when the Signal definitions GC operating program sample run is complete MA Cerity Chemical T N me 8 Operator provides Appropriate GC hardware Sufficient supplies Flow settings Sample injection 6820 Provides output to Start command Cerity Chemical Figure 2 Process for running a sample when using manual injection with Cerity Chemical for instrument control You can see from Figure 2 that e Cerity Chemical provides most of the instrument settings for you e You will need to provide or verify only the settings and supplies that Cerity Chemical cannot directly control and then make the sample injection and start command 6820 Operation 21 Introduction Important Safety Warnings Before moving on there are several important safety notices that you should always keep in mind when using the 6820 GC Many internal parts
77. g a valve configure it a Press Config select Valve and Sampling valves include a minimum input the valve number to configure sampling time and the dwell time for b Configure the valve parameters injection Switching valves include an on off setting See Configure the valves on page 74 and Valves on page 190 3 If desired load a similar method a Press Load If another method contains similar b Enter the method number then press settings you can load it if desired Enter 150 6820 Operation Overview of creating a method continued Developing Methods Step Action Notes 4 Set oven parameters 5 If using an inlet set inlet parameters 6 Set detector parameters 7 Set auxiliary zone temperatures if needed 8 Set signal parameters as needed 9 Setrun table events if needed 10 Store these parameters as a method Press Oven and enter values as needed Press Front Inlet or Back Inlet and enter values as needed Press Front Det or Back Det and enter values as needed a Press Aux and input the number of the zone 1 or 2 b Input the temperature and press Enter a Press Signal 1 or Signal 2 b Scroll to Type and press Mode Type c Scroll to the appropriate signal output and press Enter to select it a Press Run Table Mode Type b Scroll to the event type to be programmed and press Enter c Choose the appropriate signal when prompted
78. gilent Technologies assumes no liability for the customer s failure to comply with these requirements See accompanying instructions for more information Indicates a hot surface Indicates hazardous voltages Indicates earth ground terminal Indicates explosion hazard Indicates radioactivity hazard Indicates electrostatic discharge hazard peee 30 6820 Operation Introduction Electromagnetic compatibility This device complies with the requirements of CISPR 11 Operation is subject to the following two conditions e This device may not cause harmful interference e This device must accept any interference received including interference that may cause undesired operation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try one or more of the following measures 1 2 3 Relocate the radio or antenna Move the device away from the radio or television Plug the device into a different electrical outlet so that the device and the radio or television are on separate electrical circuits Make sure that all peripheral devices are also certified Make sure that appropriate cables are used to connect the device to peripheral equipment Consult your equipment dealer Agilent Technologies or an experienced technician for assistance Changes or modifications not expressly approved
79. gnal circuits to avoid overloading the circuits clamping If a chromatogram looks like A or B in Figure 35 the data needs to be scaled as in C so that all peaks are visible on the paper Ki KUL hba U i mi il A Range 0 B Range 3 C Range 1 Figure 35 Effect of range setting on chromatogram 6820 Operation 203 Additional Information for Method Developers Valid setpoints are from 0 to 13 and represent 2 1 to 213 8192 Changing a setpoint by 1 changes the width of the chromatogram by a factor of 2 The chromatograms in Figure 35 illustrate this Use the smallest possible value to minimize integration error For analog output of 0 to 1 mV 1 mV Range Attn One display unit There are limits to usable range settings for some detectors Table 38 lists the valid range setpoints by detector Table 38 Valid range settings per detector Detector Usable range settings 2 FID 0 to 13 TCD 0 to 6 ECD 0 to 6 NPD 0 to 13 Range may be run time programmed See Run Time Programming Using Run Time Events on page 153 for details Test plot The test plot shown in Figure 36 is an internally generated chromatogram that can be assigned to a signal output channel It consists of three baseline resolved repeating peaks The area of the largest is approximately 1 Volt s the middle one is 0 1 times the largest and the smallest is 0 01 times the largest 204 6820 Operat
80. gure 11 Pneumatic control grouping 104 6820 Operation Setting Flows Top regulator Middle regulator Bottom regulator Figure 12 Additional gas pressure regulators 6820 Operation The 6820 uses a set of pressure regulators and modules to control the detector and carrier gas flows In general e The pressure regulators in the left side of the GC set and regulate the maximum detector gas pressures Each detector s module provides on off control some detector modules also provide final adjustment for one or more flows e The inlet modules alone control the carrier gases but see the discussion below for exceptions Because there are several available detector configurations the gas stream s each pressure regulator controls depends on the detectors installed See Chapter 3 Controls and Components Refer to the chart below to learn which pressure regulator controls the gas stream you wish to set Note that some configurations share pressure regulators between two detectors In this case set the source pressure high enough for both detectors 105 Setting Flows 106 The regulator configurations provide sufficient range of control for most operating conditions Detector s installed Refer to this table FID TCD ECD NPD FID FID ECD FID NPD FID TCD TCD NPD NPD TCD FID TCD ECD TCD NPD ECD ECD ECD NPD Table 9 on page 107 Table 9 on page 107 Table 9
81. he TCD filament can be damaged or destroyed Turn the filament off when the TCD will not be used for extended periods For more than 1 week CAUTION Failure to turn off the TCD filament before turning gas flows off can damage or destroy it Turn the filament off before shutting down the GC gas flows If installed turn off the TCD filament Press Front Det or Back Det scroll to Filament then press Off Set all heated zones to ambient temperature and turn off the detector support gas flows Leave the carrier gas flow on When the GC is cool turn it off Turn off all gas and coolant supplies at their sources Remove the column and cap its ends to prevent contamination Store the column in a cool dry place To prevent contamination cap the inlet and detector column fittings If gas connections are removed from the GC cap the intake fittings on the back panel of the GC If desired this is a good time to replace any traps See the Maintenance and Troubleshooting manual on the 6820 User Information CD 6820 Operation Agilent 6820 Gas Chromatograph Operation 10 Additional Information for Method Developers Inlets 166 Split Splitless inlet 167 Purged packed inlet 168 Detectors 170 Flame lonization Detector 172 Thermal Conductivity Detector 177 Electron Capture Detector 182 Nitrogen Phosphorus Detector 184 Valves 190 The Column Oven 194 Signal Handling 198 Instrument Supplies 207 This section provide
82. hen selecting temperatures and flows Maximum source pressure must not exceed 100 psi Use the maximum source pressure to achieve maximum makeup flow rate Table 30 Operating parameters Gas Recommended flow range Carrier gas Packed columns 30 to 60 mL min nitrogen or argon methane Capillary columns 0 1 to 20 mL min hydrogen nitrogen depending on diameter or argon methane Capillary makeup 10 to 150 mL min nitrogen or argon methane 30 to 60 mL min typical Temperature 250 C to 400 C Detector temperature is typically set 25 C greater than the highest oven ramp temperature e Normally the carrier gas is the same as the makeup gas If the GC uses a custom configuration and the carrier gas type is different from the makeup gas type the makeup gas flow rate must be at least three times the carrier gas flow rate ECD sensitivity can be increased by reducing the makeup gas flow rate ECD chromatographic speed for fast peaks can be increased by increasing the makeup gas flow rate 183 Additional Information for Method Developers 184 ECD output If you intend to use the analog output from the ECD you must set the output Range to 10 See Setting signals on page 95 Nitrogen Phosphorus Detector The NPD passes sample and carrier through a hydrogen air plasma A heated ceramic source called the bead is just above the jet The low hydrogen air ratio cannot sustain a flame minimizing hyd
83. hifts on page 205 Pauses holds signal output at current value Resumes normal signal output Set value for selected analog output signal Does not alter digital output Set temperature of an auxiliary heated zone See also Setting Auxiliary Heated Zones on page 94 Change polarity of TCD detector See also Negative polarity on page 181 For signal events the current value is the value during the run when the event happens For related information refer to Signal Handling on page 198 Valves on page 190 6820 Operation Developing Methods To program run time events 1 Press Run Table The following message will be displayed if no programmed entries presently exist RUN TIME TABLE Table empty Use MODE TYPE to select new entry 2 Press Mode Type to see the available run time event types 3 Scroll to the event type to be programmed and press Enter 4 Choose the appropriate signal when prompted RUN TABLE TYPE Which signal Press 1 or 2 J 5 Enter values for the Time and Setpoint parameters Time the time in minutes into the run when the event will occur Setpoint if available enter the new value type mode or On Off 6820 Operation 155 Developing Methods Event number gt Total number of events RUN TBL 1 of 1 Time 0 00 lt Run time for event to o
84. hod should e Cool detector inlet and oven temperatures to ambient 25 C to save energy and preserve the column If using hydrogen carrier gas turn off the oven Turn off the TCD filament If the gas flow is set too low or if the carrier gas supply runs out while the GC is unattended the TCD filament can be damaged or destroyed Turn the filament Off when the TCD will not be used for extended periods CAUTION Failure to turn off the TCD filament before turning gas flows off can damage or destroy it Turn the filament Off before shutting down the GC gas flows For less than 1 week If you will not use the GC for up to approximately 1 week conserve gases and energy as follows 1 Reduce detector inlet and oven temperatures to 150 200 C to save energy and preserve the column 2 If using hydrogen carrier gas cool then shut off the oven before shutting off the hydrogen gas supply 3 Turn off corrosive or potentially hazardous gas flows such as oxygen and hydrogen 4 Reduce flows of carrier and makeup gases 5 Turn the TCD filament off Press Front Det or Back Det scroll to Filament then press Off Never leave flammable gas flows on if the GC will be unmonitored for long periods of time If a leak develops the gas could create a fire or explosion hazard 163 Shutting Down 164 CAUTION If the gas flow is set too low or if the carrier gas supply runs out while the GC is unattended t
85. ht will come on and stay on press Start until the run is completed The run time begins when you press Start 6820 Operation 137 Running Samples Run a Sample Using a Sampling Valve Perform this procedure when using a gas or liquid sampling valve as the injection source To run a sample using a sampling valve Step Substep Notes 1 Prepare the GC Insure that the sample flow to the valve is on 2 Prepare the sample Set the inlet flow rates Depending on the inlet these may include Column carrier flow Septum purge flow Split vent flow 3 Set the desired flow rates Set the detector flow rate s Depending on the detector these may include Column carrier flow Makeup gas flow Hp fuel gas flow Air flow Reference gas flow Anode purge gas flow 4 If using an FID light the flame 5 Load the desired method Press Load b Input the desired method number c Press Enter See page 135 See Chapter 5 Setting Flows See Chapter 5 Setting Flows See Ignite the FID flame on page 140 The Not Ready light will illuminate and stay lit until all the GC temperatures reach their setpoints 138 6820 Operation Running Samples To run a sample using a sampling valve continued Step Substep Notes 6 Wait until the Not Ready light goes off 7 Make the injection If using GC control and the method does For more information
86. ication with a remote device typically Cerity Chemical was established Clock Table Indicates that the clock table has entries 6820 Operation Controls and Components The Keyboard The 6820 keys are grouped by function as seen in Figure 5 Instant action keys Signal1 Function keys Signal2 Short cut keys Information keys Miscellaneous Run keys cog nop AAD IA OG 8 abem Options Config o k aj Numeric and modifier keys aa er a Load Store Method ae Glock Valve Figure 5 The keyboard 6820 Operation 47 Controls and Components Instant action keys Start Stop and Prep Run Function keys 48 These keys trigger the instrument to do something immediately Start and Stop Start and stop any type of run Stop also cancels a Prep Run or power fail recovery Prep Run Prepares the GC for a run when using splitless injection If you are using splitless injection press Prep Run to close the purge valve before injecting the sample Pressing Prep Run turns on the Pre Run LED This LED blinks while the instrument prepares for a run and is waiting to reach instrument setpoints other than
87. ill blink at the appropriate line of the display This helps you identify where a problem occurred OVEN Temp 30 For example a blinking z indicator here designates Init time oven failure 0 00 Rate 1 off 0 00 X 4 The detector On Off line blinks if there is a failure in the detector such as a burned out TCD filament 42 6820 Operation Controls and Components Actual and setpoint values When there are two values in one line of the display the left value is always actual and the right value is always a setpoint When there is only one value it is either an actual or setpoint depending on the parameter FRONT DET FID ee Actual value Temp Setpoint value 25 250 Output 10 6 Actual value Sounds used with the display Beeping instrument Any type of fault warning or shutdown is accompanied by one beep 6820 Operation 43 Controls and Components Messages Cautions Cautions are reminders that your instrument may be configured incorrectly or when action is required to make a setpoint For example CAUTION Instrument power must be turned off and back on for setpoint to take effect Press Clear to remove the message You can then reconfigure the instrument if desired or continue with your current configuration Errors Errors mean that e The setpoint you entered is out of the allowable range
88. in hardware related performance and operating problems In This Guide This guide assumes that you have already installed your Agilent Technologies 6820 Gas Chromatograph and verified it is working properly If not please refer to your Agilent 6820 Getting Started manual Introduction This section provides an overview of some of the 6820 GC s main features defines a few of the key terms used throughout the manual and lists critical safety precautions Strategy for Using the 6820 This section describes a helpful approach to using the 6820 if you are not using an Agilent data system It also explains some of the fundamental concepts you will apply when using the GC Controls and Components This section describes the instrument keyboard and display If you are not familiar with this instrument read this section to learn how each key functions It also explains how to make settings and interpret the information presented on the display Setting the Operating Parameters This section completely describes how to use the 6820 keyboard to make settings for all of the hardware you have installed It begins with the steps you need to take to set up configure your instrument for use and then describes how to use the inlets detectors the column oven and typical valves It also provides the procedures needed to set signal outputs Setting Flows This section describes how and where to set the gas flows used in the 6820 It al
89. ing the GC to perform an analysis you can store those settings as a method and recall them when you need to use them datasystem A data system as used in this manual refers to a computer program and any hardware the program needs such as cabling that can make GC settings collect the GC s signal output and then analyze the output and provide a report on the results run The run is your experiment Using the 6820 to separate the sample compounds and generate a detector signal is called making a run 6820 Operation Where Do Fit In 6820 Operation Introduction As the operator you will use the 6820 to collect data for analysis However the GC is only one part of the system needed to analyze a sample The other parts can include sample processing and preparation equipment specialized equipment that collects the samples for analysis and either a computer running an Agilent data system such as Agilent s Cerity Networked Data System for Chemical QA QC or an integrator If you are using an integrator the process for running a sample is similar to the process shown in Figure 1 If you are using Cerity Chemical the process for running a sample is similar to the process shown in Figure 2 19 Introduction i N P Analysis results _ gt The integrator provides the final results when the sample run is complete ahh Operator S
90. ion 6820 Operation Ready for injection display OO STATUS Controls and Components Ready for inject WARNING S Sigl buffer full Not ready display Ready display check for warnings Not ready items that are not ready If you have a Not Ready display check for faults or warnings STATUS Not Ready Oven temp FAULT S B det flame out WARNING S Fault a hardware problem requiring user intervention Warning problems that user should Sigl buffer full METHOD MISMATCH be aware of but that will not prevent instrument from executing a run The Ready Not Ready display Method mismatch message appears if hardware or user entered configuration has changed after loading a method or power on See the Agilent 6820 GC Maintenance and Troubleshooting manual for more information about error messages 53 Controls and Components The setpoint status list Press the Status key from the status display screen to bring up the setpoint status display This is a list of setpoints compiled from the current settings programmed on the instrument This is a quick way to view active setpoints during a run without having to push numerous buttons STATUS Oven temp 26 Off Signal 1 Front 0 0 Signal 2 Back 0 0 To customize the list of setpoints that you see see Configure the setpoint status li
91. ion Additional Information for Method Developers Figure 36 The test plot Test plot can be used to verify the operation of external data processing devices without having to perform repeated chromatographic runs It may also be used as a stable signal to compare the results from different data processing devices Digital signal handling of baseline level shifts Some run time operations such as changing signal assignment or switching a valve can produce large changes in the signal baseline position This can complicate signal processing by external devices The GC provides two run table commands to minimize such problems see Run Time Programming Using Run Time Events on page 153 6820 Operation 205 Additional Information for Method Developers Store sig val Saves the value of the signal at the time of the command Sig zero value Creates a new zero by subtracting the stored value from the current value of the signal and applies this zero to all future values Use these commands to surround a baseline shifting event and bring the new baseline to the previous level as shown in Figure 37 The Store sig val event must occur before the event that shifts the baseline and the Sig zero value event must occur after the baseline has stabilized at the shifted level No correction Signal Baseline level change Baseline shifting event occurs Time 3 Sig zero val event occurs Run time cor
92. ion run and the real run The same detector and column must be used operating under the same temperature and gas flow conditions Two baseline profiles may be stored as Col Comp 1 and Col Comp 2 Because the GC performs a point by point subtraction retention time shifts for example as a column ages or if flow conditions vary can cause unexpected results 408 E 15 585 9 058 6 ag 14 408 15 206 z 4 551 Chromatogram i with a rising baseline UJ PE eia Chromatogram with column compensation Blank column compensation run Figure 34 Column compensation 202 6820 Operation Additional Information for Method Developers Analog output settings zero and range If you use an analog recorder you may need to adjust the signal to make it more usable The parameters Zero and Range do this Analog zero Use to correct for baseline elevation or offsets A common application is to correct a baseline shift that occurs as the result of a valve operation After zeroing the analog output signal is equal to the Value line of the parameter list minus the Zero setpoint Zero can be programmed as a run time event For details see Run Time Programming Using Run Time Events on page 153 Analog Range Range is also referred to as gain scaling or sizing It sizes the data coming from the detector to the analog si
93. isothermal run In addition to the isothermal run you can also program up to five oven ramps See Setting up a single ramp program on page 80 and Setting up a multiple ramp program on page 81 Setting up a single ramp program 80 To set up a single ramp program 1 2 3 Press Oven to access the oven parameter list Enter a starting temperature Temp Enter the time Init time that you want the oven to stay at Temp Enter the rate Rate 1 at which the oven temperature is to increase 6820 Operation Setting the Operating Parameters 5 Enter the final temperature Final temp 1 6 Enter the time Final time 1 the oven is to hold Final temp 1 7 To end the oven ramp program after Ramp 1 set Rate 2 to zero Setting up a multiple ramp program Set up the first oven ramp as described on the preceding page In a multiple ramp temperature program the Final time for one ramp is also the Init time for the next ramp Thus there is only one Init time before Ramp 1 1 Enter the rate Rate 2 at which you want the oven temperature to increase for the second oven ramp 2 Enter the final temperature Final temp 2 3 Enter the number of minutes Final time 2 that you want the oven to hold the final temperature 4 To end the temperature program after Ramp 2 set Rate 3 to zero To add additional oven ramps repeat the steps described above Total run time Total length of a run is determined by the
94. ive column Conger or with a smaller id If you must use a large id column turn off the carrier flow long enough to allow the FID to light Check for partially or completely plugged jet Flame ionization detectors use hydrogen gas as fuel If hydrogen flow is on and no column is connected to the detector inlet fitting hydrogen gas can flow into the oven and create an explosion hazard Detector fittings must have either a column or a cap connected at all times 173 Additional Information for Method Developers 174 Conditions that prevent the detector from operating These conditions commonly prevent proper operation e Temperature set below 150 C e Inadequate air or hydrogen flow e Ignitor defective e Electrometer off Selecting FID flow rates and temperature Use the information in Table 26 when selecting temperatures and flows Table 26 Recommended temperature and flow rates FID Gas Flow range Suggested flow mL min mL min Carrier gas Packed columns 10 to 60 Capillary columns 1to5 Detector gases Hydrogen 24 to 60 40 Air 200 to 600 450 Column plus capillary makeup 10 to 60 50 Detector temperature Detector temperature should be approximately 20 C greater than highest oven ramp temperature depending on the column type The hydrogen to air ratio should be between 8 and 12 to keep the flame lit Gas pressures To select a minimum source pressure choose a flow and find its corresp
95. ix Type press Mode Type scroll to the correct type and press Enter Configure the inlets The GC knows whether or not an inlet is installed because it monitors the heater sensor connections However it does not know what kind or type of inlet is present Supply this information as follows 1 Press the Config key 2 Scroll to the Instrument parameter and press Enter 3 Scroll to the F inl type parameter 4 If the inlet type listed is either Unknown or is incorrect for the front inlet press Mode Type to select the correct type oa Scroll to the correct inlet type then press Enter 6 Press Clear 7 Ifa back inlet is installed scroll to B inl type and repeat steps 4 through 6 73 Setting the Operating Parameters Configure the Aux thermal zones The Aux auxiliary thermal zones control the heaters for devices such as a valve box or nickel catalyst To configure a thermal Aux zone 1 or 2 1 Press Config then Aux 2 Press Mode Type then select the type of device to be controlled by the zone and press Enter If no Aux thermal zones are present Not Installed appears in the display Configure the valves If one or more valves are installed configure them as follows 1 Press Config 2 Scroll to Valve then press Enter 3 When prompted input the number of the valve to configure For example to configure valve 1 press 1 The GC displays valve 1 s type 4 If the valve ty
96. keup gas flow rate Turn the detector electrometer on Ignite the flame How to Make a Setting on page 68 See To Set the Split Splitless Inlet Column and Split Vent Flows on page 117 or To Set the Purged Packed Inlet Column Flow on page 121 See To Set FID Hydrogen Air and Aux Gas Flows on page 123 See How to Make a Setting on page 68 See Ignite the FID flame on page 140 Make sure that a column is installed or the FID column fitting is plugged before turning on the air or hydrogen An explosion may occur if air and hydrogen are allowed to leak into the oven Never measure air and hydrogen together Measure them separately Thermal Conductivity Detector TCD 86 To use the TCD Step Notes 1 Install the correct column adapter See the Agilent 6820 GC 2 Install the column and check for leaks Maintenance and Troubleshooting manual See the Agilent 6820 GC Maintenance and Troubleshooting manual 6820 Operation Setting the Operating Parameters To use the TCD continued Step Notes 3 Set the detector operating temperature and turn it on 4 Set the inlet column flow rates 5 Set the detector makeup gas flow rate 6 With carrier gas flow on turn the detector filament on 7 If necessary turn Neg polarity on to invert negative going peaks See How to Make a Setting on page 68 Do not set higher than the maximum t
97. leting clock table events 146 run table events 157 stored method 67 editing clock table events 145 run table events 156 stored method 67 loading default method 66 default parameters 158 plotting a column compensation profile 98 6820 Operation programming clock table events 144 isothermal oven 80 multiple ramp oven temperature 81 run table events 155 single ramp oven temperature 80 storing a method 64 using column compensation 98 stopwatch 56 programming clock table events 145 clock time 144 145 oven temperature 196 run time 153 155 purged packed inlet flow ranges 168 flows setting 121 parameters 82 source pressure 168 Ramp key 50 ramp multiple oven 81 ramp single oven 80 range analog output 203 Rate LED 46 rate oven ramp 197 REF gas TCD 125 reference gas TCD flow 178 Remote LED 46 RS 232 communications 76 Run LED 46 Run Log key 56 Run Table key 63 run time adding events 156 deleting events 157 editing events 156 maximum 81 programming 155 total 81 run definition 18 6820 Operation S safety ECD 28 182 scrolling 41 setpoint auxiliary heated zone 94 detector 84 inlet 82 oven 79 status table 54 setpoint value 43 setpoints provided by Cerity Chemical 21 setting flows ECD 127 FID 123 purged packed inlet 121 split splitless inlet 117 TCD 125 signal analog 203 fast peaks 96 selecting output 9
98. ll say Data ok and a time and date will appear at the bottom 97 Setting the Operating Parameters Making a run using column compensation After creating a column compensation profile use it as follows 1 Set the up chromatographic conditions They must be identical to those in the stored column compensation run except that Final time in the last ramp of the oven program can be longer or shorter 2 Press Signal 1 or Signal 2 as applicable 3 Scroll to Type and press Mode Type 4 Choose Front col comp 1 or one of the other three column compensation options on the list For a description of the choices see Table 35 on page 198 5 Enter setpoints for Zero and Range if applicable See Analog data rate on page 95 for more information 6 Start your run Plotting a stored column compensation profile To look at a stored column compensation profile output it to your data system as follows 1 Press Signal 1 or Signal 2 as applicable 2 Scroll to Type and press Mode Type 3 Choose Col comp 1 or Col comp 2 4 Press Start Once the profile is output print it using your integrator or data system 98 6820 Operation Agilent 6820 Gas Chromatograph Operation 5 Setting Flows About 6820 Flow Control 100 Tips 100 Maximum operating pressure 100 Where to Measure Flows 101 Detector and column flows 101 Inlet vent and septum purge flows 103 6820 Flow Controls 104 Single detector configurations 107 Two det
99. mage the filament 6820 Operation 121 Setting Flows 122 1 Ifusing a TCD turn off the detector filament Press Front Det or Back Det scroll to Filament then press Off Locate the knob labeled CARRIER FLOW Turn it clockwise as far as it will go Do not force the knob when it closes it comes to a slightly soft stop Set the external source pressure regulator 0 07 to 0 14 MPa 10 to 20 psi higher than the pressure required on the GC internal regulator For example Does inlet use an internal regulator Pressure Yes No External regulator 0 55 MPa 80 psi 0 41 MPa 60 psi pressure Internal regulator 0 41 MPa 60 psi pressure Maximum desired 0 28 MPa 40 psi 0 28 MPa 40 psi column pressure See 6820 Flow Controls on page 104 for details on regulator usage If used set the internal 6820 carrier gas regulator pressure A typical starting value is 0 41 MPa 60 psi Carrier source pressure must be at least 0 1 MPa 15 psi greater than the maximum column head pressure Set the oven temperature to the specified initial value Wait for the temperature to stabilize Attach a flow meter to the detector outlet See Where to Measure Flows on page 101 There should be no flow at this time If there is turn the detector gas flows off Turn the CARRIER FLOW knob in the lt INCR direction to turn on the carrier gas As you open the valve the pressure reading will rise Adjus
100. mation Scroll keys A W Move the list of items up or down in the display window Your instrument only displays parameters for items that are physically present There is no way to see a parameter list for an inlet detector or other device that is not installed Keys that show many instrument functions such as Status or Config only show items that are installed Therefore the sample displays in this manual may be somewhat different than those on your instrument Symbols used in the display The cursor lt The cursor points to the line that is in editing position Changes that you make using the keyboard apply to the cursored line Asterisk A blinking asterisk prompts you to press Enter to store a setpoint or Clear to abort the entry You cannot perform any other task until this is done gt EREA FRONT DET FID Temp 25 250 If this asterisk blinks you cannot perform any other function until you press Enter or Clear Output 10 6 4 Controls and Components The asterisk on the left of a Mode Type table indicates the current selection VALVE 1 TYPE Gas sampling lt Current selection Not installed Swi h Cursor is on Gas sampling witching Pressing Enter changes the valve Other type to Gas sampling Pressing Clear keeps the Not installed original setting Blinking setpoint If the oven is shut down by the system Off w
101. n Perform this procedure when using the manual injection technique To run a sample using manual injection Step Substep Notes 1 Prepare the GC See page 135 2 Prepare the sample Prepare the sample and the syringe 3 Set the desired flow rates Set the inlet flow rates Depending on See Chapter 5 Setting Flows the inlet these may include Column carrier flow Septum purge flow Split vent flow Set the detector flow rate s See Chapter 5 Setting Flows Depending on the detector these may include Makeup gas flow Hy fuel gas flow Air flow e Reference gas flow Anode purge gas flow 4 lfusing an FID light the flame See Ignite the FID flame on page 140 5 Load the desired method a Press Load The Not Ready light will illuminate and b Input the desired method number stay lit until all the GC temperatures c Press Enter reach their setpoints 6 If making a splitless injection press After pressing Prep Run the Pre Run Prep Run LED blinks while the GC reaches its setpoints When the GC temperatures reach setpoint the split splitless inlet purge valve closes and the Not Ready LED goes off after a short delay 7 Wait until the Not Ready light goes off 136 6820 Operation Running Samples To run a sample using manual injection continued Step Substep Notes 8 Load the syringe 9 Make the injection Simultaneously inject the sample and The run lig
102. n liners see Maintenance and Troubleshooting on the User Information CD ROM 167 Additional Information for Method Developers 168 Purged packed inlet This inlet is used with packed columns when high efficiency separations are not required It can also be used with wide bore capillary columns provided that flows greater than 10 mL min are acceptable The only adjustment for this inlet is the carrier gas flow through the column Septum purge flow is set automatically based on the source gas pressure It can be measured at a vent on the front panel Changing the source pressure You can increase the upper limit of flow from a flow controller by increasing the source pressure Table 23 lists the maximum flows for the standard flow controller for a packed inlet with a 0 to 20 mL min flow restrictor at five pressures For maximum H flows read from the Helium flow column Table 23 Purged packed inlet flow rates vs source pressure Source pressure Nitrogen flow Helium flow psi mL min mL min 40 20 21 50 24 25 60 28 28 70 32 32 80 36 35 Flow ranges available You may want to change the flow range of your inlet for a number of reasons For example if you are using flows in the lowest 20 percent of a flow restrictor s range the retention times of your analysis might wander By changing from a flow of 20 mL min with a flow restriction range of 0 to 110 mL min to one with a range of 0 to 20 mL min you can elimi
103. n time begins when Output nears the Adjust offset value During equilibration Output is measured and compared to the Adjust offset value If Output stays close to Adjust offset for the entire equilibration time the detector becomes ready However if Output is too high or too low at any time during the equilibration period the adjust offset process continues and the equilibration time begins again We recommend an equilibration time of 0 0 minutes and the automatic Adjust offset process Some beads do not respond well to the automatic process For these we suggest starting at 2 0 volts and bringing up the bead voltage gradually 10 mV ata time until the desired offset is reached To change the equilibration time 1 Press Config Front Det or Config Back Det 2 Scroll to Equib time 3 Enter a value in minutes Long equilibration times reduce bead lifetime Using the NPD Verify that detector gases are connected a column is installed the correct jet is installed and the system is leak free Set oven temperature inlet temperature and column flow 6820 Operation 6820 Operation Setting the Operating Parameters To use the NPD Step Notes 1 Install the correct column adapter See the Agilent 6820 GC Install the column and check for leaks Set the detector operating temperature and turn it on Set the inlet column flow rates Set the detector makeup gas flow rate Enter Adjust offset number or pre
104. nate this problem 6820 Operation 6820 Operation Additional Information for Method Developers You can change the flow ranges in packed inlets by either e Changing the source pressure or e Changing the flow restrictor in the flow controller Changing the flow restrictor For available restrictors and the replacement procedure refer to the Agilent 6820 GC Service manual 169 Additional Information for Method Developers Detectors 170 The GC Fundamentals manual included on the 6820 GC User Information CD ROM contains details about how the detectors work and suggests starting values for your methods Table 24 summarizes the available 6820 detector systems Table 24 Detector systems Name Sensitivity Thermal conductivity Medium TCD Flame ionization High FID Electron capture Very high ECD Nitrogen phosphorus Very high NPD Responds to Everything except the carrier gas Almost all organic compounds Limited range of compounds mostly halocarbons Compounds with nitrogen or phosphorus Comments The universal detector for everything The universal detector for organics Used for trace level pesticide and herbicide analysis Used in pharmaceutical and environmental analysis 6820 Operation 6820 Operation Operating parameters Additional Information for Method Developers The operating parameters for the detectors are listed in Table 25 Table
105. nnector V2 Run time gt Valve drivers program 1th h4 1 through 4 c Connector V3 or Connector V4 Clock time program Figure 30 Internal valve drivers 6820 Operation 6820 Operation Additional Information for Method Developers There is no direct relationship between the location of a valve in the valve box and the driver that controls it This depends on how the solenoids are wired and the actuators are plumbed 193 Additional Information for Method Developers The Column Oven The GC Fundamentals manual included on the 6820 GC User Information CD ROM contains details about how the oven works and suggests starting values for your methods Capabilities Table 33 lists the capabilities of the 6820 column oven Table 33 6820 oven capabilities Capability Range Temperature range Ambient 4 C up to the configured limit Maximum temperature 425 C Temperature programming Up to 5 ramps Maximum run time 999 99 minutes Temperature ramp rates 0 to 75 C min depending on instrument configuration The oven holds two inlets and two detectors up to four valves in a heated box on top of the oven and two valves inside the oven and either capillary or packed columns 194 6820 Operation 6820 Operation Safety Additional Information for Method Developers a Oven door latch O Figure 31 Column oven For safety opening the oven door turns off power to the oven heater and fan b
106. o produce low energy electrons each particle produces approximately 100 electrons The free electrons produce a small current called the reference or standing current which is collected and measured The Ni isotope The radioactive isotope used in the cell is 63Ni It is plated onto the inner surface of the cell body and is solid at temperatures used in chromatography Some other properties are listed in Table 1 Table 1 Properties of Ni Half life 101 1 years Emission 65 87 keV max beta radiation Melting point 1453 C Dimensions of the active part Inside diameter 6 mm of the ECD Height 4 2 mm Total activity ECD cell 555 MBq 15 millicuries maximum ECD licenses Customers in China can purchase an ECD under either a General License or a Specific License Customers outside China should contact their local Agilent sales office for information The license details below reflect China s regulations Specific license Specific license ECDs require you to obtain a Materials License from the Health Bureau or local state agency permitting you to possess the amount and kind of radioisotope used in the detector You can typically ship sell or transfer the ECD to other Specific Licensees If the license permits you may also open the ECD for cleaning 25 Introduction 26 General license General license ECDs do not require a materials license You become a General Licensee automatically when y
107. o program run time events 155 To add events to the run table 156 6820 Operation 13 To edit events inthe run table 156 To delete runtime events 157 Default Method Parameters 158 To load the default parameters 158 Method Mismatch 159 User entered configuration changes 159 Hardware configuration changes 160 9 Shutting Down Shutting Down the GC 162 Create Cerity Chemical shutdown methods 162 For less than 1 week 163 For more than 1 week 164 10 Additional Information for Method Developers Inlets 166 Septum purge and inlet vent flow rates 166 Split Splitless inlet 167 Purged packed inlet 168 Detectors 170 Operating parameters 171 Flame lonization Detector 172 Thermal Conductivity Detector 177 Electron Capture Detector 182 Nitrogen Phosphorus Detector 184 Valves 190 Types of valves 190 The valve box 190 Valve control 192 14 6820 Operation 6820 Operation The Column Oven 194 Capabilities 194 Safety 195 Making atemperature programmedrun 196 Ovenramprates 197 Signal Handling 198 Signal type 198 Value 199 Digital data rates 200 Column compensation 202 Analog output settings zero and range 203 Test plot 204 Digital signal handling of baseline level shifts 205 Instrument Supplies 207 Gases 207 Traps 207 More about consumables and replacement parts 208 16 6820 Operation Agilent 6820 Gas Chromatograph Operation 1 Introduction Welcome 18 Where Do I Fitin 19 Important Safety Warnings 22
108. o the previous display e Clear error messages popup messages errors on setpoint entries etc e Cancel a function during a method clock table or run table and loading or storing methods Delete Press Delete from the status screen to delete a method run table or clock table Press Delete DELETE WHAT Press METHOD RUN TABLE or CLOCK TABLE Pressing Delete while in a run table or a clock table will prompt you to delete only the currently selected entry 62 6820 Operation 6820 Operation Storage Controls and Components The radix is a decimal place holder This parameter can be changed from the decimal point to the comma see Configure the radix type on page 73 The dash key is used to denote ranges of numbers inclusive For example to denote 1 through 3 press 1 3 This key is also used as a minus sign for negative values For example to enter 5 press 5 Table 5 lists the storage keys a brief description of their use and a place to find detailed information Table5 Method storage keys Key Use to For more information Load Load a stored method page 65 Store Store up to nine methods Stored page 64 methods are labeled and dated Method Review a list of stored methods You page 64 can load store delete or set default method Run Table View a table of events and the run page 153 time at which they occur Cl
109. ock Table Display the clock time table of events page 144 in the order that they occur based on a 24 hour clock Valve Turn valves 1 to 4 on or off For gas page 90 sampling valves this also starts the run 63 Controls and Components The method keys Load Store and Method To store a method 1 Press Method and scroll to the method number you wish to use CEEE STORED METHODS lt empty gt lt empty gt 1 2 3 lt empty gt 4 lt empty gt 53 6 lt empty gt lt empty gt I 2 Press the Store key You are then asked to confirm the store STORE METHOD Store meth 1 ENTER to store CLEAR to cancel Ma 3 Enter stores the method using the chosen number Clear returns to the STORED METHODS listing without storing the method 64 6820 Operation 6820 Operation Controls and Components 4 Ifa method with this number already exists this screen appears STORE METHOD Meth 1 exists ENTER to replace CLEAR to cancel Enter to replace the existing method with the new one and return to the STORED METHODS listing Clear to return to the STORED METHODS listing without storing the method When a method is loaded any unsaved settings are lost If you have made changes to the current method and want to keep them save the current method before loading a new one To load a stored metho
110. od Examples of this type of information are e Time and date e RS 232 communications settings e IP address e Hardware configuration settings such as auxiliary heated zone types valve types gas sampling valve loop sizes inlet types detector types etc e Oven equilibration and maximum temperature For information on how to set these parameters see Configure the Instrument on page 72 What is the difference between a 6820 method and a Cerity Chemical method for the 6820 Agilent data systems such as Agilent Cerity Networked Data System for Chemical QA QC also store methods A Cerity Chemical method contains every setting that a 6820 method does but it can also include complete information for data analysis and reporting for example integration events and parameters calibration data signal output options and reporting options While both types of method control the instrument and produce signal output only the Cerity Chemical method analyzes the data to integrate identify and report the peaks discovered 35 Strategy for Using the 6820 Operating Strategy 36 Use the following strategy for successful operation Usually step 1 is performed by the chemist who develops the analysis technique Steps 2 through 4 are performed by whoever runs the sample Operating strategy Step Notes 1 Create the 6820 analytical method 2 Prepare the GC to run samples 3 Set the GC operating conditions
111. on page 107 Table 9 on page 107 Table 10 on page 110 Table 11 on page 110 Table 12 on page 111 Table 13 on page 111 Table 14 on page 112 Table 15 on page 112 Table 16 on page 113 Table 17 on page 113 Table 18 on page 114 Table 19 on page 114 6820 Operation Single detector configurations Setting Flows Table 9 lists the functions of each pressure regulator and inlet or detector module control according to which gas is being controlled for single detector GC configurations Table 9 Controls for each gas flow in single detector GC configurations Front detector Inlet type Gas flow Setflowusingthis Module control s pressure regulator FID FID air Top AIR FID hydrogen Middle HYDROGEN FID Aux gas Bottom AUX GAS Split Splitless Carrier gas External TOTAL FLOW and COLUMN PRESSURE Purged packed Carrier gas External CARRIER FLOW TCD TCD Aux gas Top AUX GAS TCD Reference Top REF Split Splitless Carrier gas Bottom TOTAL FLOW and COLUMN PRESSURE Purged packed Carrier gas Bottom CARRIER FLOW ECD ECD Aux gas Top AUX GAS ECD Anode purge Top ANODE PURGE Split Splitless Carrier gas Bottom TOTAL FLOW and COLUMN PRESSURE Purged packed Carrier gas Bottom CARRIER FLOW NPD NPD air Top AIR NPD hydrogen Middle HYDROGEN NPD Aux gas Bottom AUX GAS Split Splitless Carrier gas External TOTAL FLOW and COLUMN PRESSURE Purged packed Carrier gas External CARRIER FLOW On Off control only 6820 Operation 107 Setting Flo
112. onding pressure from Figure 24 Set source tank pressure at least 70 kPa 10 psi or higher than the pressure used 6820 Operation Additional Information for Method Developers 80 70 FLOW mL min 49 Hydrogen 0 nal Pressure kPa 69 138 207 276 345 414 483 psi 10 20 30 40 50 60 70 700 500 FLOW mL min 400 Air 300 200 100 0 Pressure kPa 69 138 207 276 345 414 483 psi 10 20 30 40 50 60 70 Figure 24 Typical pressure flow relationships for FID gases at 25 C and 1 atmosphere pressure 6820 Operation 175 Additional Information for Method Developers The Nickel Catalyst Tube The Nickel Catalyst Tube accessory G4318A is used for trace analysis of CO and CO with an FID The gas sample is separated on the column and passed over the hot catalyst in the presence of hydrogen which converts the CO and COs peaks to CHy See Figure 25 Sample Hydrogen Air FID Carrier gas p gt Gas sample valve p Column Nickel catalyst W Figure 25 Nickel catalyst tube functional diagram Table 27 lists recommended starting flows for using the nickel catalyst Table 27 Standard FID installation Gas Flow rate mL min Carrier helium 30 FID hydrogen 30 FID air 400 Table 28 lists recommended starting flows for using the nickel catalyst with a TCD FID in series connection
113. ou purchase a ECD directly from Agilent Technologies Some states may require that you register the ECD with a state agency Certain restrictions apply to General Licenses e Owners may not open the ECD cell e Owners shall not modify the cell in any manner e Owners shall not use any solvent including water to internally clean the cell e Owners shall not interfere with or attempt to defeat the overheat circuitry that may be supplied with the ECD e Owners shall not transfer the ECD to another person or another location except as described in the applicable Regulations e Owners must perform a radioactive leak test at least every 6 months or as required by your local Agency e Owners must maintain records as required by your local Agency the Health Bureau or in certain states a state agency e Owners must notify the Agency in case of incidents or failures that might lead to a hazardous condition Additional information is available in the publication Information for General Licensees part no 5961 5664 ECD warnings Although beta particles at this energy level have little penetrating power the surface layer of the skin or a few sheets of paper will stop most of them they may be hazardous if the isotope is ingested or inhaled For this reason the cell must be handled with care radioactive leak tests must be performed at the required intervals the inlet and outlet fittings must be capped when the detector i
114. oven temperature program If some other temperature program for example a nickel catalyst temperature program is still running when the oven program ends the run terminates anyway The maximum allowable time for a run is 999 99 minutes 6820 Operation 81 Setting the Operating Parameters Setting the Inlet Parameters 82 The 6820 controls inlet temperature and mode split splitless inlet only through the keypad The inlet flow controls are located on the left side of the GC Before using your inlet for the first time make sure it is properly configured See Configure the inlets on page 73 To use your inlets Step Notes Install the correct hardware as needed Split Splitless inlet Liner Column adapter Septum Gold seal if needed Purged packed inlet Liner Column adapter Septum Insert Install the column and check for leaks Set the inlet operating temperature and turn it on See the Agilent 6820 GC Maintenance and Troubleshooting manual for the replacement or installation procedures See the Agilent 6820 GC Maintenance and Troubleshooting manual a Press Front Inlet or Back Inlet b Input the temperature setpoint and press Enter 6820 Operation 6820 Operation To use your inlets continued Setting the Operating Parameters Step Notes 4 After the inlet oven and detector reach temperature set the inlet flow s See To Se
115. pe is incorrect press Mode Type scroll to the correct valve type and press Enter Once the type is correct the rest of the valve s configuration parameters appear Scroll to each parameter and input the correct information Refer to Table 6 below Table6 Valve configuration settings Parameter Notes or value to enter Valve types Not installed No valve installed Gas sampling The valve is plumbed as a gas or liquid sampling valve You may have two sampling valves installed 74 6820 Operation Setting the Operating Parameters Table 6 Valve configuration settings continued Parameter Notes or value to enter Switching The valve is plumbed as a two position a switching valve for example to redirect flow from one column to another Other Custom plumbing Additional gas sampling valve parameters Loop volume Enter the sampling loop volume in mL Load time Enter the minimum time required to load the valve sample loop in minutes Inject time Enter the time required to flush the sample onto the column Inlet Use the Mode Type key to select the inlet Front Back or None that the valve injects into Configure the setpoint status list You can change the order of the setpoints shown in the setpoint status list For example you might want the three most important setpoints to appear first in the display when you press Status 1 Press Config Status or press Config scroll down to S
116. perature the temperatures of the inlets and detectors the amount of material inside the oven columns valves etc and whether or not this is the first run of the day Table 34 lists typical oven ramp rates Table 34 Oven ramp rates Temperature range C 120 220 230 and 240 V oven ramp rate C minute 50 to 70 75 70 to 115 45 115 to 175 40 175 to 300 30 300 to 425 20 197 Additional Information for Method Developers Signal Handling 198 Signal type The GC Fundamentals manual included on the 6820 GC User Information CD ROM contains details about how signals are handled Signal is the GC output to a data handling device analog or digital It can be a detector output or the output from temperature sensors Two signal output channels are provided Signal output can be either analog or digital depending on your data handling device Analog output is available at either of two speeds suitable to peaks with minimum widths of 0 004 minutes fast data rate or 0 01 minutes normal rate Analog output range is 0 to 1 V Digital output to Cerity Chemical software is available at 11 speeds ranging from 0 1 Hz to 200 Hz capable of handling peaks from 0 001 to 2 minutes wide Set this rate from your Cerity Chemical software The 6820 can use a large number of data as the output signal for either channel See Table 35 for a listing of the most useful options Table 35 6820 Signal choices Signal n
117. rection Signal 2 Baseline shifting event occurs 1 Store sig val event occurs Time Figure 37 Correcting baseline level shifts in digital signals 206 6820 Operation Instrument Supplies 6820 Operation Gases Traps Additional Information for Method Developers The Maintenance and Troubleshooting and Service manuals included on the 6820 GC User Information CD ROM provide more information instrument supplies One simple way to help ensure good performance is to use high quality supplies for the instrument gases and chemical traps Always use chromatographic grade carrier gas 99 9995 pure See Table 39 Dirty input gases are one of the most common causes of contamination Table 39 Gas purity recommendations Carrier gases and capillary makeup gases Helium 99 9995 Nitrogen 99 9995 Hydrogen 99 9995 Argon Methane 99 9995 Detector support gases Hydrogen 99 9995 Air dry Zero grade or better Use traps to remove residual impurities from your source gases Table 40 lists some common Agilent traps 207 Additional Information for Method Developers Table 40 Ordering information for Agilent traps with 1 8 inch fittings Item Part no Moisture S trap unconditioned 5060 9077 Moisture S trap conditioned 5060 9084 Moisture trap refillable BMT 2 Activated charcoal trap 5060 9096 Oxygen trap 0T1 2 Oxygen trap indicating IOT 2 HP Hydrocarbon S trap 40 60 mesh 5060 9096 Hydroc
118. riate method and press Delete You will be prompted with the following DELETE METHOD Delete METHOD 2 ENTER to delete CLEAR to cancel E J 2 To delete this method press Enter 3 To change your mind and not delete this method press Clear Methods can also be deleted by pressing Delete Method and entering the method number to delete 67 Controls and Components How to Make a Setting Entering setpoints There are three simple ways to enter a setting at the 6820 keypad The entry method depends on the type of setting In general you 1 Press one of the following key types Function for example Front Inlet or Back Det Miscellaneous for example Options or Config Shortcut either Temp or Ramp Method and automation for example Load or Method For this example press Front Inlet For the purged packed inlet the display reads FRONT INLET PP Temp 24 Off lt 2 Scroll to the appropriate parameter using the A V keys In this example there is only one parameter Temp 3 Enter or select the appropriate value For type selections press Mode Type to display the list of selections Scroll to the correct one and press Enter to select it For values use the keypad to enter the new value and press Enter For On Off settings press On or Off 68 6820 Operation Controls and Components In this example se
119. rm routine maintenance 1 At the keyboard press Options OPTIONS Service counter lt Calibration Communication Keybd amp Display Diagnostics 6820 Operation 6820 Operation Controls and Components 2 Scroll to Service counter Press Enter 3 Scroll to the desired counter and press Clear 4 Press Enter to set the counter to 0 or Clear to cancel Calibration Lists the parameters that can be calibrated The calibration displays are discussed in the Agilent 6820 Service manual on the 6820 User Information CD Communication Allows access to the communications setpoint parameters The communication displays are discussed in Configure your RS 232 communications settings on page 76 and in Configure your LAN communications on page 77 Diagnostics The diagnostic parameters are for use by your Service Representative Diagnostics are discussed in the Agilent 6820 Service manual on the 6820 User Information CD Keybd amp Display Use these options to set the keyboard s behavior e Keyboard lock disables keyboard setpoint changes The keyboard will still function but no setpoints can be altered while keyboard lock is enabled The Start Stop Prep Run Load and Method keys will all function normally when keyboard lock is activated Key click click sound when keys are pressed can be turned on or off e Warning beep allows you to hear warning b
120. rocarbon ionization while the alkali ions on the bead surface facilitate ionization of nitrogen or phosphorous organic compounds The output current is proportional to the number of ions collected It is sensed by an electrometer converted to digital form and sent to an output device Conditions that prevent the NPD from operating e Ifthe detector temperature is below 150 C or the oven is off the Adjust offset process will not start Gas purity Because of its high sensitivity the NPD requires very pure gases We strongly recommend that moisture and organics traps be used on the carrier gas and all detector gases including the detector hydrogen air and makeup gases The bead There are three setpoints associated with the bead Adjust offset Bead voltage and Equib time Adjust offset When you enter a value here or press On to use the stored value the bead heats and the bead voltage adjusts until Output is stable and equal to the entered value There are five stages of Adjust offset Detector off When the detector is off Adjust offset and Bead voltage are Off and initial Output is displayed Press Config Front Det or Config Back Det 6820 Operation Additional Information for Method Developers 2 Detector on detector temperature less than 150 C When you enter an Adjust offset value or press On these messages are shown in the display with the last line blinking
121. s are the exception Valves can be run time programmed but are not restored to their starting position at the end of the run You must program the reset operation in the run table if this action is desired For more information about valves see Valves on page 190 The Run Table key is used to program timed events Table 21 lists all possible the run time events The events available on your instrument will depend on the devices installed in it Table 21 Available run time events Event Data output effected Notes Valve Use to switch a sampling or switching valve Signal defn Analog and digital Set signal output type Signal zero Analog and digital Zero signal at current value Analog output the signal output becomes the raw signal minus the specified signal zero setpoint Digital output The 6820 subtracts the signal value at the time of the zero event from all future values Store sig val Digital only Stores the value of the signal at the time the event occurs See also Digital signal handling of baseline level shifts on page 205 153 Developing Methods 154 Table 21 Available run time events continued Event Data output effected Notes Sig zero value Digital only Freeze sig val Digital only Resume sig Digital only val Signal range Analog only Aux temp Det polarity Reduce signal zero by current value See also Digital signal handling of baseline level s
122. s important information about the devices available for use as well as how to use them to best advantage This information is intended as reference material for persons who are creating methods for the 6820 l i Agilent Technologies 165 Additional Information for Method Developers Inlets Table 22 An overview of inlets The GC Fundamentals manual included on the 6820 GC User Information CD ROM contains details about how the inlets work and suggests starting values for your methods The 6820 GC has two types of inlets available the split splitless capillary inlet and the purged packed inlet Table 22 briefly describes the features of each type of inlet Inlet Column Mode Sample Comments Sample to column concentration Split Splitless Capillary Split High Very little Splitless Low All Purged packed Packed n a Any All Large capillary n a Any OK if resolution All not critical 166 Septum purge and inlet vent flow rates Septum purge The septum purge line is near the septum where the sample is injected A small amount of carrier gas exits through this line to sweep out any bleed Each inlet has a different septum purge flow The purge flow varies based on the carrier gas pressure but is not adjustable Inlet vent The split splitless inlet has an additional vent used for split flow The flow from the inlet vent is not adjustable and varies depending on the column head pressure 6820 Operation 6820 Operation Ad
123. s not in use corrosive chemicals must not be introduced into the detector and the effluent from the detector must be vented outside the laboratory environment 6820 Operation Introduction WARNING Materials that may react with the 63 i source either to form volatile products or to cause physical degradation of the plated film must be avoided These materials include oxidizing compounds acids wet halogens wet nitric acid ammonium hydroxide hydrogen sulfide PCBs and carbon monoxide This list is not exhaustive but indicates the kinds of compounds that may cause damage to 63 i detectors In the extremely unlikely event that both the oven and the detector heated zone should go into thermal runaway maximum uncontrolled heating in excess of 400 C at the same time and that the detector remains exposed to this condition for more than 12 hours take the following steps 1 After turning off the main power and allowing the instrument to cool cap the detector inlet and exhaust vent openings Wear disposable plastic gloves and observe normal laboratory safety precautions 2 Return the cell for exchange Contact your local Agilent sales office for details Include a letter stating the condition of abuse It is unlikely even in this very unusual situation that radioactive material will escape the cell However permanent damage to the Ni plating within the cell is possible and therefore the cell must be returned for
124. same as Output on the detector parameter list if your signal type is Front or Back If you are subtracting one signal from another as in Front Back the Value displayed will be the difference You cannot enter a setpoint for Value A conversion factor may be involved when interpreting Value for example one FID unit is one picoamp one ECD unit is 1 Hz The units for detector and other signals are listed in Table 36 199 Additional Information for Method Developers 200 Table 36 Signal conversions Signal type One display unit is equivalent to Detector FID TCD ECD NPD 1 0 pA 1 0 x 1012 A 25 mV 2 5 x 10 V 1 Hz 1 0 pA 1 0 x 10 A Nondetector Thermal Diagnostic 1 C Mixed some are unscaled Digital data rates The GC can process data at 11 different data rates each corresponding to a minimum peak width Table 37 shows the effect of data rate selection Table 37 Cerity Chemical signal processing Data rate Hz 100 50 20 0 5 0 2 0 1 Minimum peak width Minutes 0 002 0 004 0 01 0 02 0 04 0 1 0 2 0 4 1 0 2 0 Relative noise 2 2 1 6 1 0 7 0 5 0 3 0 22 0 16 0 10 0 07 Detector FID NPD FID NPD FID NPD FID NPD All types All types All types All types All types All types Column type Capillary A to y Slow packed 6820 Operation Additional Information for Method Developers You cannot change the data rate
125. set between runs Before the oven reaches its initial setpoint and the system is thermally stable column bleed and residual peak tailing can mask an otherwise stable baseline This can waste time between runs 186 Turning hydrogen off during a solvent peak When using the NPD the baseline shifts after a solvent peak and can take some time to stabilize especially with chlorinated solvents To minimize this effect turn off the hydrogen flow during the solvent peak and turn it back on after the solvent elutes With this technique the baseline recovers to its original value in less than 30 seconds This also extends the life of the bead Turning hydrogen off between runs To extend bead life turn off the hydrogen flow between runs Leave all other flows and the detector temperature on Turn on the hydrogen flow for the next run the bead will ignite almost immediately 6820 Operation 6820 Operation Additional Information for Method Developers Bead voltage Bead voltage shows the voltage used to heat the bead It can be an actual value dependent on the Adjust offset value or can be entered as a setpoint When bead voltage is turned on you are given the option of restoring the previous setpoint or selecting a new one BEAD VOLT SETPT ENTER to restore Press Enter to set the bead voltage to the most recent setpoint in this setpoint 2 500V example 2 500 V CLEAR to cancel then reset Press Clear to
126. setting changes to occur during a day based on the 24 hour clock You can program up to 25 clock time events This collection of events is called a clock table and the GC executes it every day The 6820 has only one clock table s Agilent Technologies 141 Scheduling Clock Time Events Overview The clock table is useful for valve control loading methods and initiating blank runs Some examples of clock table use are e Load a method before you get to work in the morning so the GC is ready for use when you arrive e Load and run a method at the end of the work day after you go home to clean the column e Load a method to reduce column temperature after the work day ends then load the operating method in the morning before you arrive at work e Perform a column compensation run Program clock time events using a 24 hour clock Thus an event programmed to occur at 14 35 hours will occur at 2 35 in the afternoon Clock table events and sample runs A running analysis has precedence over any scheduled clock table events Clock table events that conflict with an ongoing sample run are skipped for that day Types of clock table events Table 20 lists all possible clock time events The list available for your instrument will depend on the hardware installed Table 20 Available clock time events Event Notes Valve Sets valve parameters Load method Loads the appropriate method Blank run Starts a blank run Prep
127. so describes how to measure flows using a typical bubble flow meter and the instrument s internal stopwatch 6820 Operation 6820 Operation 10 Running Samples This section provides guidance on how to use the 6820 to process samples and get data The general procedures provided help you determine when to perform the various tasks and functions described throughout the manual Along with the steps presented here are numerous references to the sections in the manual that will help you find any details you might need Scheduling Clock Time Events This section describes the use of clock time events Clock time events can be used to program certain setpoint changes to occur during a day based on the 24 hour clock Developing Methods This section describes advanced topics you need to develop your analytical method Read this section if you will be determining or redefining the analysis settings for your samples This section discusses what the method is a typical way in which to create new methods and how to program events to occur automatically during a run run time programming Shutting Down This section describes how to safely shut down the GC when not in use Additional Information for Method Developers This section describes how to program the instrument to perform certain tasks daily It also provides the background information that the method developer might need when creating or modifying the analytical technique
128. ss On to begin the adjustment process Maintenance and Troubleshooting manual See the Agilent 6820 GC Maintenance and Troubleshooting manual How to Make a Setting on page 68 See To Set the Split Splitless Inlet Column and Split Vent Flows on page 117 or To Set the Purged Packed Inlet Column Flow on page 121 See To Set NPD Hydrogen Air and Aux Gas Flows on page 128 You may manually adjust bead voltage to let the output reach the expected value See How to Make a Setting on page 68 and Equilibration time on page 88 Setting the Operating Parameters Controlling the Valves Make valve temperature settings using the appropriate Aux heated zone Control its use during the run as described below To use a valve Step Notes 1 Configure the valve See Configure the valves on page 74 2 Ifdesired set up a Run Table to control See Run Time Programming Using the valve Run Time Events on page 153 3 Set the valve box temperature if See Setting Auxiliary Heated needed Zones on page 94 4 lf not using Run Table control press Valve when ready to start the run Controlling valves from the keyboard The 6820 valves have two positions controlled by the On and Off keys The keyboard commands for two position valves are Valve lt valve number gt On rotates valve to one stop and Valve lt valve number gt Off rotates valve to
129. st on page 75 Miscellaneous keys 54 Time Press Time to display the current date and time a stopwatch function and information about run times The first line always displays the current date and time and the last line always displays a stopwatch The two middle lines vary as shown 6820 Operation 6820 Operation Time display between runs 9 30 10 Jun 03 Last runtime 18 05 lt Next runtime 80 00 time 0 00 0 1 t 0 00 Time display during a run rc Elapsed time 18 05 9 31 10 Jun 03 Time left 71 95 Controls and Components Actual time and date Static display of last and next runtime in minutes Stopwatch Counts time elapsed during run Counts down time remaining in run 55 Controls and Components 56 Using the stopwatch In the stopwatch mode both the time to 0 1 second and reciprocal time to 0 01 minh are displayed The stopwatch is useful when measuring flows with a bubble flowmeter 1 Press Time then scroll to the stopwatch at the bottom of the screen G 9 30 10 Jun 03 Last runtime 18 05 Next runtime 80 00 time 0 00 0 lye 0 00 lt 2 Press Enter to start the stopwatch 3 Press Enter again to stop 4 Press Clear to set to zero You can access other functions while the stopwatch is running Press Time again to view the stopwatch display
130. t Zero at the current signal value displayed 4 If using analog output scroll to Range and enter a value from 0 to 13 For more information about signal types and settings see Signal Handling on page 198 Analog data rate If using analog output to an integrator you may also need to configure the signal output data rate Analog output for the detectors can be presented at either of two speeds The faster speed allows minimum peak widths of 0 004 minutes 8 Hz 95 Setting the Operating Parameters bandwidth while the standard speed allows peak widths of 0 01 minutes 3 Hz bandwidth The faster speed is called fast peaks If you are using the fast peaks feature your integrator must be fast enough to process the data coming from the GC It is recommended that your integrator bandwidth be at least 15 Hz The availability of the fast peaks feature depends on the type of detector you have installed To use fast peaks 1 Press Config Signal 1 or Config Signal 2 2 Press On CONFIG SIGNAL 1 Fast peaks On lt Digital data rate The digital data rate is set by the Agilent data system The fast peaks feature does not apply to digital output Creating a column compensation profile 96 The GC can store two column compensation profiles Note that e The profile corresponds to the detector not the column because the 6820 does not know anything about the column 6820 Operation 68
131. t 0 28 MPa 40 psi d Use a small screwdriver to turn the variable restrictor at the center of the AUX GAS knob as necessary to obtain the correct total flow column makeup If you cannot achieve the desired flow using the variable restrictor re adjust the supply pressure 129 Setting Flows Adapters for Measuring Flow Rates Agilent provides adapters for use between your flow meter electronic or bubble and the detector exhaust vents ECD TCD and NPD The rubber adapter tube part number 5020 8231 attaches directly to an ECD or TCD exhaust vent See Figure 21 CC Figure 21 Adapter for measuring TCD and ECD and NPD exhaust flow FID A separate adapter is supplied for the FID part number 19301 60660 See Figure 22 Insert the adapter into the detector exhaust vent as far as possible You will feel resistance as the adapter O ring is forced into the detector exhaust vent Twist and push the adapter during insertion to ensure a good seal WAHA Figure 22 Adapter for measuring FID exhaust flow 130 6820 Operation Setting Flows How to Measure Flow Rates Using a Bubble Meter START Bulb line n S J This section describes how to measure flow rates in the GC using the bubble meter provided by Agilent A bubble flow meter is a very basic reliable tool for measuring gas flow It creates a bubble meniscus across a tube through which the gas is flowing The meniscus acts as a barrier and its motion r
132. t and measure to achieve the desired flow If necessary increase the source pressure 6820 Operation Setting Flows To Set FID Hydrogen Air and Aux Gas Flows 6820 Operation Hydrogen and air form a flammable mixture Do not set the hydrogen flow with air flow on Do not set the air flow with the hydrogen flow turned on If using an FID set the hydrogen fuel air and Aux gas makeup flows as described in Figure 17 On Off On Off On Off and adjustment Figure 17 FID flow controls 1 Attach a flow meter to the outlet of the detector See Where to Measure Flows on page 101 for details 2 Adjust the hydrogen flow a Turn off the AIR and AUX gases b Open the on off valve for HYDROGEN c Set the supply pressure wait for stabilization and measure the flow d Repeat 2c until the HYDROGEN flow is correct If you have flow through your column be sure to subtract it from the total flow e Close the on off valve for HYDROGEN flow while you measure AIR flow 123 Setting Flows 124 Adjust the AIR flow Make sure the HYDROGEN and AUX GAS flows are turned off Open the on off valve for AIR Set the supply pressure wait for stabilization and measure flow Repeat step 3c until the AIR flow is correct If you have flow through your column subtract it from the total flow Close the on off valve for AIR If you are using packed columns turn the AUX GAS off If you are using capillary
133. t hydrogen gas can flow into the oven and create an explosion hazard Therefore be sure that the supply is off until all connections are made and ensure that the inlet and detector column fittings are either connected to a column or capped at all times when hydrogen gas is supplied to the instrument Hydrogen is flammable Leaks when confined in an enclosed space may create a fire or explosion hazard In any application using hydrogen leak test all connections lines and valves before operating the instrument Always turn off the hydrogen supply at its source before working on the instrument The GC cannot detect leaks in inlet and or detector gas streams For this reason it is vital that column fittings should always be either connected to a column or have a cap or plug installed When using hydrogen gas check the system for leaks to prevent possible fire and explosion hazards based on local Environmental Health and Safety EHS requirements Always check for leaks after changing a tank or servicing the gas lines Always make sure the vent line is vented into a fume hood Electron Capture Detector ECD This section describes the licensing information handling precautions and safety requirements concerning the Electron Capture Detector ECD 6820 Operation 6820 Operation Introduction The ECD contains a cell plated with 63Ni a radioactive isotope 63Ni releases B particles which collide with carrier gas molecules t
134. t line of the ramp number specified If the ramp number does not exist the cursor goes to the highest ramp number defined Press Ramp 2 Cursor moves to Rate 1 line OVEN Rate 1 off 0 00 lt 6820 Operation Controls and Components Information keys Info Press Info to see context sensitive help that provides information about the active parameter line with the cursor The info messages may provide any of the following data e Definitions e Setpoint ranges e Actions to perform The following examples are possible depending upon the parameter list you are in Press Info DET OUTPUT INFO Present value of the output from this detector Dennition ERROR Out of range 0 to 425 deg C Current max 425 Set with CONFIG OVEN Setpoint ranges 6820 Operation 51 Controls and Components FF MODE TYPE INFO is present mode Move to new mode and press ENTER Perform an action Status The Status key has two parameter lists associated with it the Ready Not Ready status list and the setpoint status list The Ready Not Ready status list Press the Status key to bring up the status display This list either shows parameters that are Not Ready or gives you a Ready for Inject display If there are any Jaults warnings or method mismatches present they are displayed here See Figure 6 on page 53 52 6820 Operat
135. t the Split Splitless Inlet Column and Split Vent Flows on page 117 or To Set the Purged Packed Inlet Column Flow on page 121 5 Ifusing a split splitless inlet setthe See Configure the inlets on inlet mode page 73 See Split Splitless inlet on page 167 for more information about the inlet mode 83 Setting the Operating Parameters Setting the Detector Parameters 84 Press Front Det and Back Det to set run time parameters for the detectors or to view the detector s raw output The parameters for each detector type are described below Electron Capture Detector ECD CAUTION Electrometer The Configure Detector parameter list contains an On Off setting for the Electrometer Normally leave the electrometer on You do not need to turn it on and off when operating your ECD The only time you need to turn off the electrometer is when cleaning the detector Do not turn off the electrometer during a run It will cancel detector Output Using the ECD Verify that your detector gases are connected a column is properly installed and the system is free of leaks Set the oven temperature and the inlet temperature and flow To use the ECD Step Notes 1 Install the correct column adapter See the Agilent 6820 GC Maintenance and Troubleshooting manual 2 Install the column and check for leaks See the Agilent 6820 GC Maintenance and Troubleshooting manual 3 Set the detector op
136. t the inlet to 120 C and turn its heater on Press 1 2 0 Enter a ee A FRONT INLET PP Temp 120 Off lt Then press On FRONT INLET PP Temp 120 On lt If you enter an invalid value the GC displays an error message Press Clear then enter an appropriate value see also Configure the Instrument on page 72 6820 Operation 69 Controls and Components To turn a device On Off 70 You can easily turn the heater on or off for inlets detectors the oven and valves without changing its setpoint Press the function key for the device scroll to the temperature setting and press On or Off Some examples Front Inlet Off Turns the front inlet heater off Aux 1 Off Turns auxiliary heated zone 1 off Oven Off Turns off the oven heater 6820 Operation Agilent 6820 Gas Chromatograph Operation 4 Setting the Operating Parameters Configure the Instrument 72 Configure the oven 72 Configure the inlets 73 Configure the valves 74 Configure your RS 232 communications settings 76 Setting the Column Oven Setpoints 79 Setting up an isothermal run 80 Setting up a single ramp program 80 Setting up a multiple ramp program 81 Setting the Inlet Parameters 82 Setting the Detector Parameters 84 Electron Capture Detector ECD 84 Flame lonization Detector FID 85 Thermal Conductivity Detector TCD 86 Nitrogen Phosphorus Detector NPD 88
137. tatus then press Enter 2 Scroll to the setpoint that should appear first and press Enter This setpoint will now appear at the top of the list 3 Scroll to the setpoint that should appear second and press Enter This setpoint will now be the second item on the list 6820 Operation 75 Setting the Operating Parameters 76 4 Continue editing until the list is in the order you wish Press Config Status a Scroll to Signal 1 and press Enter r CONFIGURE STATUS Oven temp Time left Fr inlet temp Bk inlet temp Signal 1 lt Signal 2 b Signal 1 is now the first item on the list CONFIGURE STATUS Signal 1 lt Oven temp Time left Fr inlet temp Bk inlet temp Signal 2 Configure your RS 232 communications settings Normally the 6820 will be configured for proper RS 232 communications at the factory However if you need to check or alter the communications settings do so as follows 1 Press Options scroll to Communication and press Enter 2 Scroll to each RS 232 setting press Mode Type and select the new value as needed Table 7 lists the recommended settings Table 7 RS 232 communications parameters and default values Parameter Default value for use with Cerity Chemical Baud rate Handshake Parity Data bits Stop bits End of command 19200 UART None 8 1 LF
138. ter 5 Setting Flows describes how to set gas flow rates Agilent Technologies 37 seo 209 wre Controls and Components GC Control and Component Locations There are two types of controls on the 6820 electronic controls and flow controls The electronic controls are used for tasks such as turning the instrument on making program settings and starting or stopping a run The flow controls set the gas flows Figure 3 shows the locations of the general GC components controls and switches It also points out the location of other GC parts that you will use frequently Detector cover Display Run status display Flow controls S S L SSpS Keyboard Q Column oven door S85 SS aag On Off switch Oven door latch Front view Back inlet R e Back detector Front inlet Front detector Top view detector cover removed Figure 3 Location of 6820 controls and components 38 6820 Operation Controls and Components e To open the detector cover lift it It tilts up e To open the oven lift the oven door latch at the bottom right of the oven door 6820 Operation 39 Controls and Components Keyboard and Display Display The title and several lines of messages or parameters are visible Status board LEDs show information about the current state of the instrument
139. tronic control to automate many of the instrument control functions These settings can be entered using the keypad and display before each run or they can be stored and recalled for use when needed Storing the settings is the easiest way to consistently prepare the GC for a run This collection of settings is called a method The 6820 can store nine methods each consisting of the following e Oven run time temperature profile including temperature ramps e Front Back inlet temperature settings e Front Back detector temperature settings e Signal settings e Heated valve box and similar device control settings and temperature profile e Valve run time settings and configuration data type sample loop size etc Run time events All of these settings are explained in detail in later sections of this manual The operating procedures presented here assume the use of stored methods when preparing for a sample run 34 6820 Operation 6820 Operation Strategy for Using the 6820 Nonstorable experiment settings The following settings are not storable in methods e Flow Pressure settings Gas flows are manually controlled e Clock table events The clock table is not storable For information on the clock table Programming the Clock Table on page 144 Stored configuration settings In addition to the information stored in the method the GC also stores its current hardware configuration outside of any meth
140. ube Connect flow meter in line at this connection ECD FID exhaust port FID TCD outlet port TCD NPD outlet port Figure 9 Location of column exhaust for detectors 102 6820 Operation Inlet vent and septum purge flows Setting Flows The inlet vents exhaust through fittings in the inlet module front panels See Figure 10 To measure an inlet vent or septum purge flow connect directly to the front panel fitting Split Splitless inlet Inlet vent TOTAL FLOW Septum purge vent Purged packed inlet Septum purge vent INLET VENT SPLIT SPLITLESS PURGED PACKED CARRIER FLOW VENT SEPTUM PURGE COLUMN HEAD PRESSURE VENT SEPTUM PURGE Figure 10 Location of inlet and purge vent fittings for inlets 6820 Operation 103 Setting Flows 6820 Flow Controls Flow and pressure controls The flow and pressure controls available on the instrument depend on the inlets and detectors installed Inlet and detector modules are installed in the left side of the GC as shown in Figure 11 and Figure 12 Front detector flow controls oo Back detector flow controls Front inlet flow controls O Back inlet flow controls o O o Fi
141. upplies default values for most parameters if you do not specify them These values are reasonable operating parameters for inlets and detectors Once you change a parameter the default value for that parameter is erased At some time you may find it desirable to reload the default parameters Doing this erases all current parameters the active method and replaces them with the default set This does not change stored methods To load the default parameters 1 Press Method 2 Scroll to the Set default method line and press Enter 3 This message will appear SET DEFAULT METH ENTER to load default method CLEAR to cancel L J 4 Press Enter to load the default parameters 158 6820 Operation Method Mismatch Developing Methods Method mismatch messages appear when the method you load contains parameters that do not match the GC s current configuration If this happens the parameters that do not match may be ignored Mismatches are caused by user changes different configuration for an inlet or valve for example or by hardware changes replace a TCD with an FID etc made after the method was stored User entered configuration changes 6820 Operation You will be warned of user entered configuration changes between the stored method and the active method The GC assumes that since the active method is most recent it contains the correct configuration data Therefore the GC
142. ut maintains the setpoints in memory OVEN Temp 350 Door open lt Init time 2 00 Rate 1 off 0 00 sa d Closing the oven door returns the oven to normal operation 195 Additional Information for Method Developers If the oven cannot attain or maintain an entered setpoint temperature during normal above ambient operation the GC assumes a problem exists and turns the oven off For more information about oven shutdowns please see the Agilent 6820 GC Maintenance and Troubleshooting manual Making a temperature programmed run You can program the oven temperature from an initial temperature to a final temperature using up to five ramps during a run A single ramp temperature program raises the initial oven temperature to a specified final temperature at a specified rate and holds at the final temperature for a specified period of time as shown in Figure 34 Final temp Final time Temp Init temp Init time Figure 32 Single ramp The multiple ramp temperature program is similar You can program the oven from an initial temperature to a final temperature but with various rates times and temperatures in between Multiple ramps can also be programmed for temperature decreases as well as increases 196 6820 Operation 6820 Operation Additional Information for Method Developers Oven ramp rates The highest rate that you can achieve depends on many factors including the room tem
143. ves can be configured as switching The main differences between sampling and switching valves are e The plumbing connections How the valve interacts with the run The GC incorporates the sampling valve more directly into the run process valve actuation corresponds with the start of data collection On the other hand a switching valve can be activated at any time during the run and does not correspond to a start command For more information on the capabilities of valves and a full listing of typical valve applications available on the 6820 contact your local Agilent sales office Figure 29 shows a top down view of the 6820 The valve box is located on the top of the oven between the inlets and detectors Open the detector cover to access it 6820 Operation Inlets Heated zone 1 Additional Information for Method Developers Back of GC Valve Valve box Detectors Heated zone 2 Figure 29 The valve box 6820 Operation Top view of 6820 with detector cover up Heating the valves The valve box can contain up to two heated blocks the shaded areas in Figure 29 each with two valve mounting locations The middle hole on each block is used to pass tubing into the column oven If using one or two valves mount them on the same block This allows them to be heated using only one control channel Aux 1 or Aux 2 depending on how the heaters are
144. wired If using more than two valves both Aux 1 and Aux 2 must be used for heating them Set them at the same temperature For configuration information see Configure the Aux thermal zones on page 74 Agilent recommends configuring the Aux zones for valves as shown in Figure 29 191 Additional Information for Method Developers Valve control 192 Carrier gas flow through valves There are two ways that a valve can be plumbed to the column directly or through a split splitless inlet If plumbed directly you will need a separate pressure regulator to control the column carrier flow If plumbed through the split splitless inlet control the carrier flow using the inlet module A valve driver is the set of software and circuitry in the GC that controls the valve There are four drivers Valve 1 through Valve 4 Table 32 lists the control characteristics for these valve drivers Table 32 Valve driver characteristics Type Volts Power or current Use Current source 24 VDC 13 watts Pneumatic valve control The typical valve used on the 6820 is pneumatically operated The valve actuator air connected to the GC routes to solenoids mounted near the GC s main printed circuit board This circuit board controls a solenoid for each valve and the solenoids are plumbed to each valve s actuation mechanism Keyboard Solenoid wiring bracket m Connector V1 or m Co
145. ws Pressure regulator ks Top Middle kO Figure 13 and Figure 14 give examples of control locations for two typical GC configurations QJ Bubble meter i m Z AUX GAS OT C INLET VENT VENT SPLIT SPLITLESS SEPTUM PURGE Inlet 1 Column Figure 13 Example Gas flow controls for a single FID with split splitless inlet 108 6820 Operation Setting Flows Pressure regulator D ee REF Purged Packed CARRIER FLOW SEPTUM PURGE Column Figure 14 Example Gas flow controls for a TCD with purged packed inlet 6820 Operation 109 Setting Flows Two detector configurations Table 10 through Table 18 list the functions of each pressure regulator and inlet or detector module control according to which gas is being controlled for two detector GC configurations Table 10 Controls for each gas flow for two FIDs Gas flow Inlet type Set flow using this Module control pressure regulator Front FID air Top AIR Front FID hydrogen Middle HYDROGEN Front FID Aux gas Bottom AUX GAS Back FID air Top AIR Back FID hydrogen Middle HYDROGEN Back FID Aux gas Bottom AUX GAS Carrier gas Split Splitless External TOTAL FLOW and COLUMN PRESSURE Carrier gas Purged packed External CARRIER FLOW On Off control only Table 11 Controls for each gas flow for front ECD and back FID Gas flow Inlet type Set flow using this Module control pressure regulator
146. wse to the CD and run the file setup exe This installation program will put shortcuts in your computer s Start menu that will link to the manuals either copied to your computer s hard drive or on the CD ROM In Microsoft Windows 2000 and XP these shortcuts will be installed in the following path by default Start All Programs Agilent 6820 XP Start Programs Agilent 6820 2000 Alternately you can browse the CD ROM and open the files directly The documents listed below are designed to quickly and easily guide you through the process of installing and verifying the performance of the 6820 GC Installation Poster Start here This poster provides an overview of the installation process and summarizes important safety information about the instrument For each installation step find detailed instructions in the Getting Started manual Getting Started Read this during installation and setup This guide provides detailed site preparation information and the step by step instructions you will need to 1 Prepare your working space 2 Provide the appropriate GC supplies 3 Install the GC hardware Daily Use and Operation When You Need More Information 4 Install the GC software if using Cerity Chemical 5 Configure the GC for use 6 Verify that the GC is working properly By following these steps you will also learn some simple but important operating tasks that you will perform frequently Operation this manu

Agilent 6820 Gas Chromatograph Operation

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