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Ambient Liquid Sampling Steps: 1. Load the method for the desired analysis on the ChemStation software. 2. Verify that the injection source in the CS software is correct. Select “Instrument > Select Injection Source”. It should be set to “GC Injector”. 3. Fill a 1.5ml vial with the desired sample. 4. Put the vial in the sample vial position in the turret on the auto sampler. Check the solvent wash vial to ensure that it is full, and the waste vial to ensure that it is empty. 5. At the Chem Station software, select “Runcontrol>Sample Info”. Enter the information for the current sample. Make sure there is a vial number in the “Location” field; otherwise no injection will be made. 6. Select “Runcontrol>Run Method” at the Chem Station software. The injection will wash the syringe, inject sample and wash the syringe again according to the parameters set in method. The software will automatically start data collection when the injection is made.
Ambient Liquid Sampling Steps: Load the method for the desired analysis on the ChemStation software Verify that the injection source in the CS software is correct Select “Instrument > Select Injection Source” It should be set to “GC Injector” Fill a 1.5-ml vial with the desired sample Put the vial in the sample vial position in the turret on the auto sampler Check the solvent wash vial to ensure that it is full, and the waste vial to ensure that it is empty At the Chem Station software, select “Runcontrol>Sample Info” Enter the information for the current sample Make sure there is a vial number in the “Location” field; otherwise no injection will be made Select “Runcontrol>Run Method” at the Chem Station software The injection will wash the syringe, inject sample and wash the syringe again according to the parameters set in method The software will automatically start data collection when the injection is made Gas sample Injection Load the method for the desired analysis on the ChemStation software Connect the sample vessel or process line to 1/8” fitting labeled “Gas sample Inlet #1” If necessary, press [Pre-run] at the Agilent Technologies 7890B keypad to set the gas chromatography from saver mode to run mode Open the sample vessel or process line to the sample inlet at a purge flow rate of approximately 20-30 ml/min If the gas flow meter is used, the flow should be under 10ml/min Note: For a valid external standard calibration, the sample must be injected at the same pressure and/or flow rate This can be accomplished by purging the sample, turning off the sample pressure, and the allowing the pressure within sample loops to equilibrate to ambient pressure (use a bubler for the determination) or by running the flow rate at a constant set point Press “Start” at the Agilent Technologies 7890B gas chromatograph keypad or allow Chem Station to start the gas chromatograph remotely With the sample flow turned off to the GC, disconnect the sample vessel or process line from GC All sample must be filtered against particulates The correct filter for a gas sample should be a to 15 micron “F” series NUPRO in line filter or equivalent Recommended Maintenance Items Septa Symptoms - Retention time increase - Peak areas change - Ghost peaks Recommended Action When using syringe injections, replace every 50 to 100 injections Inlet liners Ferrules - Columns - Filters - Tailing peaks Nosy baseline Tailing peaks Loss of polar peak area Ghost peaks Mass discrimination Poor repeatability Poor retention time repeatability Tailing peak Excessive gas consumable Noisy baseline Broad peaks Tailing peaks High bleed (significant baseline rise) Shorter retention times Increase noise and drift Ghost peaks Declining column performance Replace with every other septa change or when dirty Replace when making new connection or check old connections for leaks Replace when performance no longer meets requirements Replace when performance cannot be changed with other column fixes such as heating column overnight at elevated temperatures Replace every two or four cylinders of gas or as indicating traps require Valve Runtime Events Occasionally it may become necessary to adjust or edit the runtime events The valve runtime events can be changed with the following keystrokes: Press [Run table] Scroll to the desired valve event using [] Enter the desired time in minutes and press [Enter] To add a valve event to the run tables use the following keystroke: Press [Run table] Press [Mode/Type] Press [Valve] Press number of the valve for the event Enter the desired time in minutes when the event should occur and then press [Enter] Press either [On/Yes] or [Off/No] to choose the valve position for the event 7693A ALS Prerun Checklist Use this checklist before running analyses to make sure that the sample vials and sampler are ready Sample vials are at least half full Sample vials are at least half full Sample vials are at least half full Vial cap is centered, with no wrinkles, and the septum is flat Sample vials are at least half full Sample vial positions match the run parameters Sample vials are at least half full Each solvent bottle contains 4.5 mL of fresh solvent Sample vials are at least half full Waste bottles are empty Sample vials are at least half full Syringe door is closed Sample vials are at least half full Sufficient solvent and waste capacity is available for sample vials Sample vials are at least half full Syringe is new or clean Sample vials are at least half full Syringe design and size are correct Sample vials are at least half full Plunger is secure in plunger carrier loop Sample vials are at least half full Needle is aligned with septum retainer nut Sample vials are at least half full Syringe is rinsed with solvent Sample vials are at least half full GC inlet liner is clean and deactivated Sample vials are at least half full GC inlet liner or insert is correct type for injection technique Sample vials are at least half full GC inlet septum type is correct Sample vials are at least half full GC inlet septum has sufficient life remaining Sample vials are at least half full Correct septum nut is installed in GC inlet Use the following vials and septa to use highly inflammable solvents such as carbon disulfide The the bottle Carbon septa and caps are designed disulfide is a highly flammable solvent with a boiling not to fall inside point of46.2 °C, a flash Point of -30 °C and an ignition point of 90 °C, and is designated as a special inflammable material in Hazardous Substances Category IV of Japan’s Fire Service Act Carbon disulfide chromatographs is Care occasionally used is required as a solvent on gas in its use since it has low boiling and ignition points and is highly toxic 2.5 Selecting the Septum for the Sample Injection Unit White (standard type) Standard accessory silicon septum Shimadzu Standard type (pack of 20) P/N 201-35584 Blue (long-life (LL) septum) Septum featuring both low bleed and long life Shimadzu LL long life (pack of 20) P/N 221-48972-91 Brown (high-temperature (HT) septum) Bleed amount is less when used at high temperatures compared with LL septa Shimadzu HT for high-temperature use (pack of 20) P/N 221-48398-91 Green (Thermogreen septum) Least influence of plasticity but hard Shimadzu Thermogreen LB-2 (pack of 10) P/N 221-35507-01 ATTENTION The type of bleeding differs with each septum and appears as a different pattern on chromatograms For high-sensitivity analysis, be sure to select and use a septum that does not allow bleeding to appear at locations that will obstruct the peak of the target compound After extraction for several hours by hexane etc., performing conditioning for several hours at a temperature between about 120 °C and 150 °C (up to about 200 °C for LL and HT septa) is sometimes effective in decreasing bleeding Elastic syringe for AOC-20i The syringe plunger is made of titanium Because it is less likely to generate abrasive dust originating from metal, the syringe is less likely to seize (ít bị tắc, nghẹt) , making it ideal for samples that contain water ATTENTION Microsyringes are made to extremely high precision So, be sure to use the original syringe body and plunger set The syringe alone cannot be used as a replacement part