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108

User Information

Developing Methods

Developing Methods

This chapter discusses various parameters that can affect the 
sensitivity, precision, and accuracy of an analysis.

The tendency of a material to go into the gaseous phase is the 
partition coefficient, K, where C

c

 is the concentration of the 

analyte in the condensed phase (the sample matrix) and C

g

 is 

the concentration of the analyte in the gaseous phase (the 
headspace). The partition coefficient, K is related to the degree 
of solubility that the analyte has in the matrix. For example, 
benzene is not very soluble in water, and has a K of 
approximately seven. Ethanol, which is very soluble in water, 
has a K of 7000. A high value of K implies it is difficult for the 
analyte to leave the matrix and go into the headspace. See 

Figure 15

 for an illustration of the particle coefficient.

K is also very dependent on temperature, as demonstrated by 
the following equation:

Figure 15

Illustration of partition coefficient

Equilibration

K =

C

c

C

g

dK

dT

--------

1

T

2

-------

=

medium_standard.book  Page 108  Tuesday, February 17, 2004  10:14 AM

Содержание G1888

Страница 1: ...Agilent Technologies Agilent G1888 Network Headspace Sampler User Information medium_standard book Page 1 Tuesday February 17 2004 10 14 AM...

Страница 2: ...onsequential damages in connec tion with the furnishing use or per formance of this document or of any information contained herein Should Agilent and the user have a separate written agreement with w...

Страница 3: ...to enter new setpoints for each function 4 Advanced Functions Describes the advanced functions controlled by the Adv Fctn menu how to edit setpoints for these functions and the displays that accompany...

Страница 4: ...g the Instrument Describes maintenance procedures including changing the sample loop transfer line needle valves and EPROM 10 Troubleshooting and Error Messages Lists the possible causes and solutions...

Страница 5: ...ent electronics 17 Many parts are dangerously hot 18 Gases 18 General warnings 19 Safety and Regulatory Certifications 20 Information 20 Symbols 21 Electromagnetic compatibility 21 Sound Emission Cert...

Страница 6: ...ssurization 37 Filling the sample loop 38 Loop equilibration 39 Injecting the sample 39 End of cycle and vial recovery 40 Modes of Operation 41 Standard headspace extraction 41 Multiple headspace extr...

Страница 7: ...ons 65 Advanced Function Descriptions 67 Stabilize Time 67 Parameter Increment 68 Vial number and location 70 Keyboard Lock 71 Manual Operation 72 Pressure Units 73 Stored Method 74 Multiple Headspace...

Страница 8: ...oring and Loading Methods 102 Storing a method 102 Loading a method 103 Chaining Methods 104 Activate a Method Chain 104 Deactivate a Method Chain 105 Using a Method Chain for MHE 106 7 Developing Met...

Страница 9: ...pressurization flow using EPC 124 9 Maintaining the Instrument Maintenance Schedule 126 Common Replacement Parts and Consumables 127 Removing the Loop Cover 130 Changing the Sampling Probe 132 Changin...

Страница 10: ...cibility 170 Carryover in air or solvent blanks 171 Unwanted background noise or peaks 172 Vial Handling 173 Vial not dropped 173 Remove all vials 173 210 Tray too slow error 173 211 Tray motor encode...

Страница 11: ...Headspace Sampler pressure reading 179 Pressures are below normal operating pressures 179 Synchronization With GC Start or GC Ready GC Does Not Start 180 Communication Between the PC and Headspace Sa...

Страница 12: ...12 User Information medium_standard book Page 12 Tuesday February 17 2004 10 14 AM...

Страница 13: ...ostatic discharge is a threat to instrument electronics 17 Many parts are dangerously hot 18 Gases 18 General warnings 19 Safety and Regulatory Certifications 20 Information 20 Symbols 21 Electromagne...

Страница 14: ...to develop methods use the sampler to carry out analyses and maintain and troubleshoot the sampler For site preparation requirements and checkout procedures see the G1888 Network Headspace Sampler Sit...

Страница 15: ...operating maintenance and troubleshooting information for the G1888 Network Headspace Sampler This manual describes using the Headspace Sampler in standalone mode However many of the procedures covere...

Страница 16: ...e setpoint 2 Text in Bold means that you should press the key by that name Be careful how you enter information For example the key sequence Menu 1 Enter indicates that you should press the Menu key t...

Страница 17: ...electronics boards in the instrument The internal wires and cables connected to these boards The wires for any heater such as the oven Electrostatic discharge is a threat to instrument electronics Th...

Страница 18: ...ance 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 Gases Do not use flammable carrier gases Do...

Страница 19: ...plumbing to prevent a potentially hazardous condition To avoid a potential shock hazard when using liquid solution to locate leaks turn the main power switch off and disconnect the main power cord Be...

Страница 20: ...1 du Canada The instrument is designed and manufactured under a quality system registered to ISO 9001 Information The Agilent Technologies Headspace Sampler meets the following IEC International Elect...

Страница 21: ...hnologies assumes no liability for the customer s failure to comply with these requirements Electromagnetic compatibility This device complies with the requirements of CISPR 11 Operation is subject to...

Страница 22: ...its 4 Make sure that all peripheral devices are also certified 5 Make sure that appropriate cables are used to connect the device to peripheral equipment 6 Consult your equipment dealer Agilent Techno...

Страница 23: ...and wipe down with a damp lint free cloth Recycling the Product For recycling contact your local Agilent sales office Table 1 Fuses Fuse designation Location Fuse rating and type F2 F3 Power line mod...

Страница 24: ...24 User Information Introduction medium_standard book Page 24 Tuesday February 17 2004 10 14 AM...

Страница 25: ...atics 32 General operation 34 Power on diagnostics 35 Standby Condition 36 Vial pressurization 37 Filling the sample loop 38 Loop equilibration 39 Injecting the sample 39 Modes of Operation 41 End of...

Страница 26: ...cent of ethanol in human blood to see if a driver is legally intoxicated The ease with which a sample forms a gaseous headspace depends on the sample s partition coefficient See Developing Methods on...

Страница 27: ...peak areas versus the extraction number are plotted to obtain quantitative data about the compound of interest MHE is often used as a calibration tool Once the peak area versus the concentration is es...

Страница 28: ...the operator Up to four different methods can be stored and used to analyze a series of samples The Headspace Sampler can also do multiple headspace extraction MHE using multiple septum punctures with...

Страница 29: ...8 Network Headspace Sampler User Information 29 Figure 1 Overview of the G1888 Network Headspace Sampler from the front of the instrument Transfer line Screen Keypad Sample tray medium_standard book P...

Страница 30: ...ates the air to maintain constant and uniform temperature The carousel can shake at two speeds to help components elute into the headspace quicker Mechanical rods move vials down into the oven and up...

Страница 31: ...50 C Vial tray The 70 sample vial tray is located on top of the unit to the left of the oven The tray is constructed of a flexible belt with dividers for each vial compartment The keypad on the front...

Страница 32: ...ure regulator when the Headspace Sampler is set for manual pressure control MPC When the Headspace Sampler is set for electronic pressure control EPC the GC provides all flow and pressure control Togg...

Страница 33: ...Transfer line Flow controller Six port injection valve Pressure sensor board Toggle switch Figure 5 Vial pressurization gas pneumatic system for the Headspace Sampler Sample loop Six port injection va...

Страница 34: ...n the oven at this time The oven sample loop and transfer line heat to reach the setpoint values The display reads Not Ready until the oven sample loop and transfer line reach their setpoints If you p...

Страница 35: ...messages may appear as well If you receive other messages see Troubleshooting and Error Messages on page 163 Figure 6 Startup diagnostics ROM check OK RAM check OK Serial IT00410010 Vent Valve Press...

Страница 36: ...to the GC injection port through the sample valve See Figure 7 Figure 7 Standby condition S1 is open Carrier gas flow Mass controller Pressure transducer Vent Sample loop To GC Auxiliary gas flow for...

Страница 37: ...he vial The pressurization valve opens allowing gas to enter the vial for the pressurization time The valve then closes again See Figure 8 Figure 8 Vial pressurization S1 is closed vial raised on need...

Страница 38: ...low more analyte to be injected A longer loop fill time 10 to 15 seconds equilibrates the loop pressure to atmospheric pressure See Figure 9 Figure 9 Loop fill S1 is closed S2 is open to fill the loop...

Страница 39: ...ows through the sample loop and the transfer line into the GC inlet port This sweeps the sample into the GC See Figure 10 Figure 10 Injection S1 and S2 are closed Carrier gas flow Mass controller Pres...

Страница 40: ...See Figure 11 The default vent time for S2 is 30 seconds To adjust the vent time see Vent Valve purging on page 84 Figure 11 Purge S1 is open S2 is open for 30 seconds Carrier gas flow Mass controlle...

Страница 41: ...ain the same incubation interval during the gas chromatographic run the Headspace Sampler transfers vials one by one into the oven and recovers each vial after sampling More than one vial can be prese...

Страница 42: ...two cases are Situation A total preparation time of 30 minutes with a run cycle time of 15 minutes Situation B total preparation time of 15 minutes with a run cycle time of 30 minutes Figure 12 Instr...

Страница 43: ...tion time 7 The vial fills with pressurization gas 8 Vial sampled Sample loop fills 9 Sample loop equilibrates 10 Headspace Sampler makes the headspace injection and triggers a GC start 11 The vial re...

Страница 44: ...after the Vial Equilibration Time elapses Each subsequent extraction occurs based on the Vial Eq time interval For example if Vial Eq Time 8 0 min and Cycle Time 5 0 min then first extraction is at 8...

Страница 45: ...btain a good log area versus extraction number graph for quantitative work if appropriate temperature and equilibration times are set Multiple Headspace Extraction Conc mode In this MHE mode the Heads...

Страница 46: ...46 User Information Introduction to Headspace and to the G1888 Network Headspace Sampler medium_standard book Page 46 Tuesday February 17 2004 10 14 AM...

Страница 47: ...tions 50 Enter 50 Clear 50 Numeric keypad 50 Tray Advance 50 Start Stop key 51 The Active Method Key 52 Zone Temps 52 Event Times 54 Vial Parameters 57 Menu Key 58 Load Method 59 Store Method 60 Chain...

Страница 48: ...f the setpoint for the highlighted parameter Editing setpoints To edit a setpoint 1 Navigate to the parameter 2 Key in the new value using the numeric keypad 3 Press Enter to make the new value part o...

Страница 49: ...t Stop Starts Stops and or resets a run Active Method Displays a menu for editing method parameters Menu Displays the main menu for access to advanced functions and loading storing and chaining method...

Страница 50: ...itions of the Headspace Sampler The decimal key is used for menu shortcuts Tray Advance Press this key to enter the Tray Advance screen and manually position the tray Press the cursor keys while in th...

Страница 51: ...ts an inadvertent run interruption To stop press the key again To continue the run press Clear When the sampler stops during a run the vials in the oven automatically return to the sample tray The met...

Страница 52: ...mps sets temperature values for various heated zones in the sampler Procedure Use the cursor keys to scroll to OVEN LOOP or TR LINE Transfer Line to set temperature values Enter a new value using the...

Страница 53: ...the oven Table 3 Zone temperature ranges Heated zone Allowed setpoint range Default value C Oven 40 230 in 1 C increments 50 Loop 45 250 in 1 C increments 60 Tr Line 50 250 in 1 C increments 70 The mi...

Страница 54: ...estimate of the cool down time required if any The GC cycle time must be long enough for the GC to become ready This time allows the Headspace Sampler to introduce samples into the oven efficiently a...

Страница 55: ...gas mixture passes through the sample loop to vent This fills the sample loop with a precise amount of headspace gas Loop Eq Time loop equilibration time Time after the vent valve closes to allow the...

Страница 56: ...nges See page 54 for descriptions of each event Table 4 Event time setpoints Event Allowed setpoint range min increments Default Value min GC Cycle Time 1 0 999 9 in 0 1 25 Vial Eq Time 0 999 9 in 0 1...

Страница 57: ...e lower than the first vial number The Headspace Sampler will give an error message and you will need to re enter the vial number Shake Shake specifies the agitation level of the oven carousel during...

Страница 58: ...n Store Method see page 60 For more information on Chain Method see page 61 For more information on Pressures see page 62 For more information on Advanced Functions see page 64 DIAGNOSTIC READY Store...

Страница 59: ...nalysis Note that loading a method overwrites the current method in active memory Procedure Use the numeric keypad to enter a number between 1 and 4 Press the Enter key to load the method stored in th...

Страница 60: ...ber between 1 and 4 Press the Enter key to store the method in that storage area DIAGNOSTIC Store Method Store Method Chain Methods Pressures STORE METHOD Load Method 1 4 CAUTION Storing a method over...

Страница 61: ...current method in active memory Procedure Use the numeric keypad to enter two to four numbers between 1 and 4 Press Enter to chain the methods together Enter 0 on the numeric keypad to disable the ch...

Страница 62: ...tlet of the pressure regulator before the in line restrictor See page 32 for a diagram of the pneumatics system and the location of the pressure sensor boards The pressures screen is a read only displ...

Страница 63: ...tion 72 Pressure Units 73 Stored Method 74 Multiple Headspace Extraction 75 Check for Ready 76 Reset 78 Valve Count 79 Vial Size 80 Zone Calibration 81 LAN Configuration 82 MAC Address 83 Enable RS232...

Страница 64: ...is greater than 9 use a decimal point followed by the second digit of the menu number For example press 2 to select menu item 12 4 Some Advanced functions contain subfunctions such as Zone Calibration...

Страница 65: ...he shutter and open and close all valves on the Headspace Sampler 5 72 PRESSURE UNITS Changes the pressure units 6 73 STORED METHOD Load one of five preset methods 7 74 MULTI HS EXTR Sets parameters f...

Страница 66: ...witching from RS232 to LAN 6 83 PURGE VALVES Forces pressurization gas out the vent to purge the line 7 84 LEAK TEST Starts running the leak test 8 86 DIAGNOSTIC Displays firmware revision RAM ROM sta...

Страница 67: ...ing its initial setpoint before vials are loaded into the oven Selecting Stabilize Time displays the following Procedure Enter the number on the keypad and then press Enter to set the value One minute...

Страница 68: ...plays are 0 0 which means that the parameter increment is off The two parameters are mutually exclusive if a nonzero number is entered into one the other is automatically set to zero Oven Temp Step En...

Страница 69: ...tion increases the temperature from run to run in the headspace vial only The loop and transfer line temperatures remain at their original setpoints Be sure to set the loop and transfer line temperatu...

Страница 70: ...laced into tray position 1 The first number on the left of the screen is the first oven carousel position The last number on the right of the screen is the sixth oven carousel position In this example...

Страница 71: ...thod Selecting Keyboard Lock displays a small graphic of a lock on the top level screen Procedure To lock the keyboard use the cursor keys to scroll to LOCKED and press Enter Scroll to UNLOCKED and pr...

Страница 72: ...to restore motors to their default state See page 78 Procedure Use the cursor keys to scroll through the menu of items Carousel and Tray Press 1 to rotate clockwise 1 position Press 0 to rotate count...

Страница 73: ...e Tray Lifter is raised Sample V Press V and Vent V Press 1 to turn the valve on Press 0 to turn the valve off Pressure Units Description This function changes the pressure units for the displays amon...

Страница 74: ...60 110 110 110 150 Tr Line 70 115 115 120 180 Equilibration time min GC cycle time 25 0 5 5 2 0 2 0 6 0 Vial eq time 15 0 7 0 7 0 1 5 5 0 Pressuriz time 0 20 0 08 0 08 0 20 0 1 Loop fill time 0 20 0...

Страница 75: ...vailable on the Headspace Sampler If MHE is set to ON the HS sends a start signal to the GC after each extraction If MHE is set to CONC the HS sends a start signal to the GC after the final extraction...

Страница 76: ...ignal If Check For Ready is active then the sampler will check for the presence of a ready signal from the GC just prior to injection If a GC ready signal is not found the sampler waits aborts or cont...

Страница 77: ...GC readiness This mode corrupts constant heating time if the GC cycle time is not complete when the constant heating time is reached 5890 Abort The sequence aborts if the 5890 GC is not ready when the...

Страница 78: ...until all setpoints for the method are reached The last method in use before the reset remains in effect After the reset the Headspace Sampler asks if it should recover vials from the oven carousel Ch...

Страница 79: ...t move in both directions on and off before the counter increments Procedure To reset the counter use the cursor keys to highlight Reset Counter Press Enter The following screen appears Press Enter to...

Страница 80: ...or 20 mL vials The HS cannot use 10 mL and 20 mL vials together in the same method Procedure Use the cursor keys to select the appropriate Vial Size and press Enter 10 Reset 11 Valve Count ADV FUNCT...

Страница 81: ...be restored to factory defaults at this screen The menu choices Reset Oven Defaults and Reset Loop Defaults only appear if a custom offset exists See Zone Calibration on page 156 for more of the cali...

Страница 82: ...n the screen Press Enter to accept the number or Clear to cancel The highlight automatically moves to the next value after entering a number Enable RS232 must be turned off before using the Headspace...

Страница 83: ...ce Sampler Disable the RS232 port to enable the LAN port Procedure Use the cursor keys to select Yes to enable RS232 or No to disable RS232 and enable the LAN port ACT MAC Address 00 20 4A 32 10 3B Ru...

Страница 84: ...Standby Purge This function opens the vent valve and allows pressurization gas to escape through the vent Use this function to remove any traces of unwanted material from the Headspace Sampler plumbi...

Страница 85: ...V2 Standby Purge Select V2 Standby Purge with the cursor keys and press Enter Use the key pad to key in a time value between 1 and 999 minutes Press Enter The value appears in the SET column The ACT c...

Страница 86: ...ociated with restrictions include No peaks Loss of sensitivity Restrictions are often caused by the swelling of the solenoid vent valve seals or the build up of residues in the vent tube Symptoms asso...

Страница 87: ...OK RAM check OK Serial USOOOOLP22 DIAGNOSTIC DIAGNOSTIC RUNNING Firmware rev A 01 01 ROM check OK RAM check OK Serial IT004410010 DIAGNOSTIC DIAGNOSTIC RUNNING Vent Valve Press Valve OK Lifter Tray O...

Страница 88: ...the power on system diagnostic messages DIAGNOSTIC RUNNING Shutter Tray Carousel OK Oven Sensor OK OK OK Loop Sensor OK DIAGNOSTIC DIAGNOSTIC RUNNING Trans Line sensor LAN interface Vial press sensor...

Страница 89: ...5 Preparing a Sample Sample Preparation 90 Loading the Sample Tray 92 This chapter describes the steps necessary to prepare a sample for analysis including filling and sealing a sample vial and loadin...

Страница 90: ...pace gases do not escape prematurely For crimp top vials use a crimper Agilent part no 9301 0720 designed for headspace vials with 20 mm caps to seal the vials Screw caps Agilent part no 5188 2759 and...

Страница 91: ...ossible to turn the cap If the cap turns easily recrimp the cap The crimping tool may need adjustment 10 To decap vials use a decapper for vials with 20 mm caps part no 5181 1214 NOTE Vials will conta...

Страница 92: ...er to move the desired loading position to the very front of the sample tray Using the cursor keys advance tray positions one by one while adding vials until all samples are loaded into the tray Do no...

Страница 93: ...7 Setting Vial Parameters 100 Storing and Loading Methods 102 Storing a method 102 Loading a method 103 Chaining Methods 104 Activate a Method Chain 104 Deactivate a Method Chain 105 Using a Method Ch...

Страница 94: ...e allowed range Press any non numeric key to remove the error message Press Clear to remove an incorrectly typed keystroke while entering setpoint values The Clear key also returns to the top level of...

Страница 95: ...n C Key in the desired value for the oven temperature setting followed by Enter The allowed range for this setting is 40 230 C in increments of 1 C New value ACT SET Loop C ZONE TEMPS 50 50 Oven C 60...

Страница 96: ...emperature Use the cursor keys to highlight Tr Line C Key in the desired temperature followed by Enter The allowed range for this setting is 50 250 C in increments of 1 C NOTE As a general rule the lo...

Страница 97: ...dspace Sampler is running samples Changes are applied to the next vial analyzed You cannot change parameters for a vial currently being sampled The keys involved are locked Navigate to the EVENT TIMES...

Страница 98: ...on Time The Vial Equilibration Time is the time the vial spends in the oven heating to form the headspace gas Use the cursor keys to highlight Vial Eq Time min Key in the desired value followed by Ent...

Страница 99: ...vent valve closes This allows the analytes in the sample loop to equilibrate to the higher loop temperature and allows the pressure and flow in the loop to stabilize Use the cursor keys to highlight...

Страница 100: ...t Vial Param from the Active Method menu The sampler displays the following For more information on vial parameters see Vial Parameters on page 57 Setting the First Vial First Vial specifies the locat...

Страница 101: ...Last Vial cannot be lower than the number of the First Vial If the Last Vial location is lower than the First Vial location the Headspace Sampler gives an error message and the Last Vial location mus...

Страница 102: ...Enter The Headspace Sampler stores the current method in the specified memory location A stored method includes the following parameters Zone Temps Event Times Vial Parameters The advanced functions f...

Страница 103: ...the following screen 2 Use the cursor keys to highlight Load Method 3 Enter the location desired 1 4 on the numeric keypad followed by Enter The method stored in the specified location is now availab...

Страница 104: ...To activate a Method Chain 1 Press Menu This displays the following screen 2 Use the cursor keys to highlight Chain Method Press Enter 3 Key in the method sequence in the order to be run up to four me...

Страница 105: ...Actual chain 1 2 3 Methods run in order from left to right on the display This method sequence is active until you edit it or load a new method Deactivate a Method Chain To deactivate a Method Chain 1...

Страница 106: ...e for each extraction To run an MHE 1 Key in the parameters for Zone Temps Event Times and Vial Parameters for the method See page 94 2 Store this method in one of the four storage locations See page...

Страница 107: ...Times 111 Vial equilibration time 111 Loop fill time 111 Matrix Effects 113 Changing the Sample Loop 114 Sample Size 115 Vial Pressurization and Time 116 Vial pressurization 116 Vial pressurization t...

Страница 108: ...rtition coefficient K is related to the degree of solubility that the analyte has in the matrix For example benzene is not very soluble in water and has a K of approximately seven Ethanol which is ver...

Страница 109: ...the sensitivity of the headspace analysis The following operations can be used to decrease K 1 Add mineral salts such as NaCl or Na2SO4 to the matrix aqueous samples 2 Add another liquid to the matrix...

Страница 110: ...ion of the headspace vial could be dangerous Unstable compounds could degrade at elevated temperatures There are two ways you can program the Headspace Sampler to increase oven temperature in steps Us...

Страница 111: ...n page 68 to increase the Vial Equilibration Time for each successive sample in the series Then plot the peak area versus equilibration time for a certain peak The system is at equilibrium when this c...

Страница 112: ...is greater the analyte will be more concentrated and consequently more sample will be injected into the GC A length of restrictive tubing can be attached to the Swagelok fitting labeled vent on the ba...

Страница 113: ...s but water miscible systems dilute the sample with water This decreases the solubility of most organic molecules in the sample and increases their concentration in the headspace Matrix effects are im...

Страница 114: ...sample injection for trace analysis might be desired A 3 mL loop is available See Changing the Sample Loop on page 134 NOTE A larger sample injection may broaden some peaks especially on a capillary c...

Страница 115: ...fluenced by the relative amount of the gas and condensed phases in the sample vial Increasing the sample size may give corresponding increases in peak areas If sensitivity is not an issue small sample...

Страница 116: ...ossible to make or buy a pressure gauge fitted with a needle that could be used to determine the actual vial pressure developed under your time and temperature conditions Set the method vial pressuriz...

Страница 117: ...f the sample loop into the GC without causing peak broadening For example for a packed GC column that gives 15 second wide peaks flow would be at least 6 mL min for a 1 mL loop This will sweep out the...

Страница 118: ...118 User Information Developing Methods medium_standard book Page 118 Tuesday February 17 2004 10 14 AM...

Страница 119: ...itions 121 Flow rates 121 Setting the carrier gas flow rate using MPC 122 Setting the vial pressurization gas pressure using MPC 123 Setting carrier flow using EPC 123 Setting vial pressurization flow...

Страница 120: ...the Headspace Sampler See page 121 3 Set the GC conditions See the GC operating manual 4 Load the method or set the method chain See Loading a method on page 103 or Activate a Method Chain on page 104...

Страница 121: ...ut its flow systems See Figure 17 for the location of the Headspace Sampler pressure regulator and flow controller Make sure that the EPC MPC toggle switches on the underside of the Headspace Sampler...

Страница 122: ...meter to the GC split vent Turn up the headspace carrier gas flow until the flow rate out the split vent equals the flow rate desired in the column The split ratio is 1 1 This flow rate equals the col...

Страница 123: ...ssurization flow path A setting of 10 to 20 psi is usually high enough To read the actual pressure value press Menu and choose Pressure from the menu The pressure displays in the right side of the win...

Страница 124: ...ary channel in the GC Auxiliary channels 3 4 and 5 are the most common Set the vial pressurization gas higher than the pressure inside of the vial to prevent a backwards flow from contaminating the vi...

Страница 125: ...hecking Alignments 139 Checking the tray chain tension 139 Checking the position 1 sensor alignment 140 Checking the tray shutter motor group alignment 140 Aligning the carousel 142 Leak Testing Gener...

Страница 126: ...ses High boiling solvents OVI blood alcohol analysis 70 User type 1 User type 3 70 User type 2 User type 4 Table 8 Recommended maintenance schedule Maintenance activity User type 1 User type 2 User ty...

Страница 127: ...est kit For capping the transfer line and other connections G1888 60701 Vial kits 20 mL flat bottom Headspace crimp top vials silver aluminum one piece crimp caps with safety feature molded PTFE butyl...

Страница 128: ...ransfer line needle od 0 5 for split splitless inlet Deactivated steel 2322590004 Transfer line needle od 0 7 for split splitless inlet Deactivated steel 2322590005 Strain relief septum nut 6410090050...

Страница 129: ...9733 1 ampoule of standard 1 mL 1 pkg of 5 mL micro pipettes Material Safety Data Sheet Certificate of Analysis PM Kits G1888A PM kit with 1 mL loop G18888 60702 G1888A PM kit with 3 mL loop G18888 60...

Страница 130: ...steps in Table 10 Table 10 Removing the loop cover Step Action Notes 1 Open the pneumatics cover a Raise the lid of the sampler b Use a Phillips screwdriver to loosen the two screws at the front of th...

Страница 131: ...the loop cover a Loosen the two screws on the loop cover b Remove the cover Table 10 Removing the loop cover continued Step Action Notes Cover screw Loop cover front Cover screw Loop cover top medium_...

Страница 132: ...ling probe Table 11 Changing the sampling probe Step Action Notes 1 Remove the loop cover Follow the steps on page 130 2 Remove the heater block covering the sampling probe a Loosen the Phillips screw...

Страница 133: ...the figure below Do not bend any tubing when installing or the coating will break and compromise inertness 4 Remove the sampling probe Grab the sampling probe with tweezers and remove it from the uni...

Страница 134: ...ver Follow the steps on page 130 2 Loosen the bolt holding the back of the loop mandrel to the manifold body Use a 7 mm wrench to loosen the bolt shown below 3 Remove the plumbing from the six port va...

Страница 135: ...take care not to bend the loop when installing it or you will break the coating and compromise inertness 5 Reverse the steps given above to reassemble the Headspace Sampler Perform a leak test on fitt...

Страница 136: ...Table 13 Replacing the tubing assembly Step Action Notes 1 Remove the loop cover Follow the steps on page 130 2 Remove the heater block covering the sampling probe and tubing assembly a Loosen the Ph...

Страница 137: ...8 mm wrench to secure the connection at the solenoid fitting and a 7 mm wrench to turn the connection on the tubing b Disconnect the fitting from port 6 of the 6 port valve Use a 7 mm wrench Table 13...

Страница 138: ...bend the tubing when installing it or you will break the coating and compromise inertness 6 Reverse the steps given above to reassemble the Headspace Sampler Perform a leak test on fittings before rep...

Страница 139: ...ay is not properly tensioned the chain links can rotate around their hinges and prevent the vial from centering over the shutter hole during vial delivery The result is a Vial Not Dropped error Perfor...

Страница 140: ...Press 5 on the keypad 3 Verify that the detail on the tray chain link lines up with the dimple on the tray wall See Figure 20 If it does not align call an Agilent service representative Checking the...

Страница 141: ...ually check that the shutter is not touching the edge of the tray base See Figure 22 Figure 21 Motor group alignment Lifter Shutter Figure 22 Shutter alignment Shutter Tray base No rubbing medium_stan...

Страница 142: ...ine up The result is lifter errors Perform the following visual check 1 Open and lock the lid 2 Locate carousel position 1 It is marked with one small indentation 3 Use the advanced function Manual Op...

Страница 143: ...ion 143 If the elevator rod and bushing do not line up exactly under the hole in the carousel cylinder call Agilent service Figure 23 Carousel alignment Indentation Tray lifter medium_standard book Pa...

Страница 144: ...C headspace installations Chromatographic symptoms such as loss of sensitivity can result from leaks and restrictions Use the following set of tests for verifying leaks and restrictions within the Hea...

Страница 145: ...Purge Split vent trap Column Sample S1 S2 Flow Needle Headspace vial PS FS PCV1 PCV2 Headspace Sampler GC restrictor loop valve 40 60 psi FS PS Flow sensor Pressure sensor Legend gas in purge flow S1...

Страница 146: ...ge Split vent trap Column Column flow ZDV union ZDV Sample S1 S2 Flow Needle Headspace vial PS PS FS PCV1 PCV2 Headspace Sampler GC gas in restrictor Aux bleed fitting loop valve union 4 mL min Total...

Страница 147: ...ctions to the inlet such as needle and septum zero dead volume union and volatiles inlet Connections to the 6 port sampling valve Zero dead volume union above the sampling probe In some applications r...

Страница 148: ...ic tool located on the CD ROM Setup 1 Attach the 1 8 inch od tubing to the vent with a Swagelok connection Finger tighten the connection 2 Place the free end of the tube in a beaker of water 3 If need...

Страница 149: ...s After 0 2 minutes the pressurization valve closes The vent valve opens for 0 3 minutes The vented air flows through ports 1 3 5 and 6 of the sampling valve Watch the beaker of water The valve clicks...

Страница 150: ...ressure to equalize across manual pneumatic controls and the flow restrictor 2 Seal the flow path 3 Monitor the pressure for 5 minutes 4 Check the results The pressure should decay less than 2 psi ove...

Страница 151: ...a leak Be sure that the leak is not at the transfer line A leak in the carrier flow path indicates a possible leak at port 2 or 3 of the 6 port valve A leak in the vial pressurization flowpath indicat...

Страница 152: ...decay of more than 2 psi over 5 minutes indicates a leak If there is a leak call an Agilent service representative If there is no leak proceed to step 4 4 Tighten or reconnect the carrier gas connect...

Страница 153: ...rform the following steps to run the pressure decay test 1 Open the shutoff valves on the back of the Headspace Sampler 2 Wait 5 minutes for the flow paths to pressurize and equilibrate 3 Turn off the...

Страница 154: ...f the 6 port valve proceed to part 4 Otherwise press Clear to end the leak test Pressure decay test part 4 6 port valve inject mode optional This section consists of two pressure decay tests The tests...

Страница 155: ...Sampler 7 Print Table 19 Record the time and initial pressure values in the table 8 Allow 5 minutes to pass Record the final time and pressure values in Table 19 Carefully close the lid of the sample...

Страница 156: ...alibration process may take days to complete Once completed the custom offsets are stored in memory on the main processor PCA If this PCA fails the custom offset cannot be restored Do the following as...

Страница 157: ...n Notes 1 20 mL sample vial and cap Recommend vial part number 5182 0837 and cap and septum part number 5183 4477 1 No 1 Phillips head screw driver Used for accessing the loop heated zone 1 High tempe...

Страница 158: ...e the cursor keys to highlight Oven Calibration from the Zones Calibration screen Press Enter 3 Place the temperature probes a Lift the lid of the Headspace Sampler and place the vial with temperature...

Страница 159: ...key until the setpoint is displayed on the screen Open the lid of the oven to allow cooling Record the temperature reading in Table 20 6 Enter temperature measurements a The Headspace Sampler display...

Страница 160: ...igure 26 and Table 23 below for fuse locations and part numbers WARNING Fuse replacement should be performed only by qualified service personnel Figure 26 Fuse locations on the power supply Power supp...

Страница 161: ...designation Location Fuse rating and type F2 F3 Power line module 10A 250V glass tube F3 Terminal near transformer 8A 250V glass tube F3 F4 Power board 6A 125V glass tube F1 Power board 1A 250V glass...

Страница 162: ...162 User Information Maintaining the Instrument medium_standard book Page 162 Tuesday February 17 2004 10 14 AM...

Страница 163: ...ing 173 Vial not dropped 173 Remove all vials 173 210 Tray too slow error 173 211 Tray motor encoder error 173 212 Tray position 1 error 174 220 Shutter error 174 230 Tray lifter error 174 240 Sample...

Страница 164: ...hronization With GC Start or GC Ready GC Does Not Start 180 Communication Between the PC and Headspace Sampler 181 Internal Communication Serial I O Errors 182 Memory and Processor Errors 183 Blank Di...

Страница 165: ...ge Chromatographic results No peaks 168 Reduced sensitivity 168 Poor retention time reproducibility 169 Poor area count reproducibility 170 Carryover in air or solvent blanks 171 Unwanted background n...

Страница 166: ...does not match Headspace Sampler pressure reading 179 Pressures are below normal operating pressures 179 Synchronization with GC start or GC ready GC does not start 180 Communication with PC Run metho...

Страница 167: ...no self test at power on fans running 184 Instrument dead Power on sampler no response 185 Lost method in active memory Loaded new method or chained methods and lost the method in active memory 185 Ta...

Страница 168: ...sure inside the sample vial after equilibration for EPC vial pressurization gas usually 10 to 20 psi Use the inlet pressure setting for EPC carrier gas The sample vial Check for the sample vial for cr...

Страница 169: ...flow to the inlet Check for restrictions that block the flow path for filling the sample loop The flow path starts at the sample probe and runs to the bulkhead fitting See Leak Test on page 148 Check...

Страница 170: ...ount reproducibility If Check for Ready is set to 5890 Wait or APG Wait vial equilibration times may vary Increase the GC Cycle Time or select a different Check for Ready setting The equilibration of...

Страница 171: ...lvent blanks decreases by a factor of 5 to 10 for each run the carryover is probably due to an unswept area Check the following There is flow from the GC inlet to sweep the inlet weldment Check the tr...

Страница 172: ...nce of internal or calibration standard directly into the inlet If there are no unrecognized peaks the problem is not in the GC Check the following in the Headspace Sampler Possible contamination in s...

Страница 173: ...al handling error or after pressing the stop button The message indicates that the sampler found vials in an unexpected carousel location See Recovering from a vial delivery error on page 177 210 Tray...

Страница 174: ...uction or cannot find its home position Check for obstructions in the shutter area and check the tray shutter group alignment See Recovering from a vial delivery error on page 177 Call an Agilent serv...

Страница 175: ...ncoder senses an obstruction or cannot find its position Check and clear any obstruction to the carousel Check the carousel alignment See page 142 See Recovering from a vial delivery error on page 177...

Страница 176: ...from a vial delivery error on page 177 Tray full This error appears when the sampler tries to recover vials after a vial handling error or after pressing the stop button The message indicates that th...

Страница 177: ...omatic vial recovery routine may cause the same error a second time See Checking Alignments on page 139 5 Reset the Headspace Sampler with Advanced Function 10 see page 78 or power cycle the instrumen...

Страница 178: ...ow to respond or does not reach the setpoint check the following The oven lid is closed and the latches locked The loop heated zone cover sits flush with the base of the pneumatic compartment The line...

Страница 179: ...GC pressure readings The instruments use a different type of sensor and the two sensors are calibrated using a different process If there are severe differences in the pressure check for leaks and re...

Страница 180: ...tion With GC Start or GC Ready GC Does Not Start If the Headspace Sampler does not start the GC check the following The Remote Start Stop cable connection The Check for Ready setting Advanced Function...

Страница 181: ...address are compatible on the same network The Enable RS 232 setting is OFF See Advanced Function 16 on page 83 The LAN address is correct See Advanced Function 14 on page 82 Reset or power cycle the...

Страница 182: ...r Messages Internal Communication Serial I O Errors These errors indicate a bad connection between the main processor PCA and peripheral PCAs Call an Agilent service representative medium_standard boo...

Страница 183: ...s User Information 183 Memory and Processor Errors These errors result from defects in firmware or a defective main processor PCA Call an Agilent service representative medium_standard book Page 183 T...

Страница 184: ...lts from an interrupted or incomplete firmware update The instrument fans are running there is no self test and the display is lit but blank Call an Agilent service representative to run the Recover f...

Страница 185: ...ies of the instrument Check the following Headspace Sampler line module fuses are open or blown Check the power selector switch setting Fuses will blow if switch is set to 115 VAC and the line voltage...

Страница 186: ...ethod or chaining methods There is no warning message before overwriting the method in active memory This is not an error Be sure that the method in active memory is stored in one of the four storage...

Страница 187: ...ety 18 Setting the flow rate using EPC 123 Setting the flow rate using MPC 122 Standby condition 36 Chain methods 61 104 Multiple headspace extraction 106 Parameter increment 69 Varying event times 11...

Страница 188: ...Overview of headspace analysis 26 Methods Advanced function stored method 74 Chain 61 104 Developing 108 Entering 94 Load 59 103 Store 60 102 Multiple Headspace Extraction Advanced functions 75 Multi...

Страница 189: ...T Temperatures Entering values 52 Times Entering setpoints 54 GC Cycle Time 54 Inject time 55 Loop equilibration time 55 Loop fill time 55 Pressurization time 55 Vial Equilibration 55 Transfer line De...

Страница 190: ...190 User Information Index medium_standard book Page 190 Tuesday February 17 2004 10 14 AM...

Страница 191: ...medium_standard book Page 191 Tuesday February 17 2004 10 14 AM...

Страница 192: ...Agilent Technologies Agilent Technologies Inc Printed in USA March 2004 G1888 90012 medium_standard book Page 192 Tuesday February 17 2004 10 14 AM...

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