• Retention time problem

    Good morning, we have a GC-MS with a DB-HeavyWax Column. Yesterday we changed the column for a new one (the same). The retention times of our samples shifted 8-11 min. Now, the peaks appear 8-11 min later. We are usi...
    last modified by ebosinceanu
  • Unknown peak co-eluting with MeOH on DB-624 GC-FID

    Hello,   I am injecting ethanol samples by direct injection which contain trace amounts of methanol and notice the methanol peak varies injection to injection on the same sample. I also injected pure air (empty ...
    created by chemist23
  • GC-MS annual verifcation failing linearity, causes?

    Hi, GC-MS:7890B/5977B I am injecting 0.2, 0.4, 0.6, 0.8, 1.0 uL/mL solutions of 1-octanol to verify GC-MS system for linearity. Besides improper solution preparation, what else can I do to improve the the injection ...
    last modified by chemist23
  • 6890/7890/8890 Actuators for rotary GSV valves

    Hello Agilent,   One of my colleagues has ordered a replacement actuator (part.no.: 19325-60660) for activating a two-position 10-port rotary valve for GSV injection on a 7890B gas chromatograph. The old actuato...
    last modified by topsoe-lak
  • GC Sensitivity Test

    I'm doing Injection Sensitivity test for GC using FID Performance Evaluation Sample Kit. I'm not using an Integrator, I'm using ChemStation. I know that the typical amount obtained using ChemStation is around 4000 pA*...
    last modified by sergio.echavarri
  • GC and ALS firmware - latest revisions for download?

    Hello Agiilent,   Where do we find information regarding the latest available Agilent instrument firmware revisions for download?   Best regards - Lars
    last modified by topsoe-lak
  • Agilent 6890 Faulty Pneumatic Board

    Hi everyone.   I have a Agilent 6890 with ALS, and I have problems with the EPC. The message that display is :   Pneu Error 0158 PCB Cmd Error: 2003   Anyone knows how to fix this? Best Regards.
    last modified by joao.andradee
  • Compound concentrations increasing???

    We analyzed effluent samples via our GCMS system paired with an ATOMX purge and trap. All of a sudden, we have noticed a big increase in certain compounds concentrations and can't explain why. Typically, we make thre...
    last modified by jenileehaddon
  • precolumn

    If I have a 2 m precolumn, when I introduce the length of the column in my instrument method, do I have to add to my principal column length? p.e. Precolumn length 2 m, column 15 m, total 17 m What if the precolumn h...
    last modified by iliana
  • Tailing of unretained species in GC-MS

    See pic below. We use a HS-GC/MS for biological specimens. I recently did some method development and noticed that the unretained species is tailing so bad that my early eluter target is out of acceptance criteria. I ...
    last modified by tsutch
  • GC USP Alcohol method for methanol limit test injection had retention time shift

    GC USP Alcohol method for methanol limit test injection had retention time shift from 3.5 minutes with ~10M area counts to 20 minutes with area count 700K. Checked or replaced liner/O-ring, septum, carrier gas fl...
    last modified by patrick.s.nam
  • How many injections were made?

    Hello,   I would like to know how many injections were made on a 7820A Agilent GC between 2 dates. Is there a way through the software (Openlab CDS Chemstation GC Agilent) to find this information? Thank ...
    last modified by csiquet_flex2000
  • Updating Agilent 8890 with GC Firmware breaks Inlet maintenance menu?

    The menu "Inlets Maintenance" (Maintenance/Front Inlet) is showing ALS counters after upgrading Agilent GC 8890 to firmware to v2.1.0.626. Pressing the "Perform Maintenance" link text only allows for "Replace Syringe"...
    last modified by cbm
  • supply voltage PSI module

    Hello! I have a qustion. how can i see the supply voltage on the module PSI ? Azrael
    last modified by azrael
  • 1.17 MS1 RF driver cannot maintain the requested mass setting

    Hello everybody! GC MS (7000C triple quad) shows error "1.17 MS1 RF driver cannot maintain the requested mass setting" when we perform EI high sensitivity autotune and ms goes to standby mode. We finally performed aut...
    last modified by madi.omirzak
  • Back Detector loses air flow when Front is on

    Using the Agilent 7890A. Column installed with no leaks detected. Both the front and back detector are set to 300°C, gas Flow Rates - Hydrogen: 45mL/min, Air 450mL/min and He 1.0mL/min. The split flow is 80mL/min...
    last modified by gcchem179
  • Manual Steps for Inlet Leak Check, Pressure Decay Test, and Split Vent Restriction Test for 6890/7890

    The following are the manual steps for performing the standard inlet tests for 6890 and 7890A GCs. Typically, one runs the Inlet Leak Check to confirm whether there's a leak (the leak rate you determine is only approx...
    last modified by valentinrusu
  • FID Jets for Agilent 8890 GC compared with 5890/6890/7890 GC

    Hello,   I have just changed a FID weldment from "FID adaptable fitting" to "Capillary optimized fitting" on a Agilent 7890A GC. The FID jet dimensions mounted in the new FID weldment are quite new to me... Ther...
    last modified by topsoe-lak
  • GC 6890 Oven not heating up

    Hello, my GC 6890 oven is not heating up. I already checked the flapper operation and it is working properly. My next guess would the oven heater or the oven sensor. Could it be something else? Maybe the oven heater f...
    last modified by sergio.echavarri
  • Clean CG liner

    Dear Community, hello ¿It's possible to clean my CG liner? This is the number part: 5183-464 (Inlet liner, split, single taper, glass wool, deactivated, low pressure drop)   Thank you!
    last modified by mgomez