'Starting GC Prerun but GC not idle''


We have a PAL RSI 85 connected to a Agilent 7890B GC. We perform either headspace or liquid analyses using this autosampler. Sequences are set up in software program "Chronos" which send the needed info to Masshunter for each injection. Since recently, when using the liquid injection tool Masshunter gives an error after Chronos has send the info: "Starting GC Prerun but GC not idle", see picture of log below. Resulting this the injection can't be started. After this we can start the chronos sequence manually in masshunter and the GC ready signal is sent to Chronos, leading to injection and start of the GC program. Due to this we can't run sequences of multiple samples anymore, which really slows us down. We use Masshunter B.07.04.2660.

Can anybody help us with this issue, it will be greatly appreciated?

  • If it was working before - what changed?  Can you try an older method that worked?  Does it still function normally with headspace methods?

    MassHunter B.07.04.2660 was released November 2015 on now unsupported Windows 7 64 Bit SP1 -- has the operating system been upgraded? Any Microsoft updates loaded?

  • Hi Paul,

    Thank you for taking your time to respond. As far as we know, nothing has changed. We did notice that the number of times the GC won't start when using the liquid injection tool on the Pal has increased, from used to happen sometimes to most of the time. That's also something that seems odd to us, sometimes a sequence can be run without any issues.

    We don't have this issue when using the headspace or ITEX tool on the sampler.

    The operating system is Windows 7, version 6.1.7601 Service Pack 1 Build 7601. We use this with update KB4499175.

  • If it does not happen using the headspace or ITEX tool, there is probably not a hardware problem.  Make a new method starting from default and use a simple method name with simple data subdirectory and data file names -- making sure that the total data file name with path is <40 total characters and does not have any special characters or blank spaces.  It might save you some characters by making a D:\data directory to use instead of d:\GCMS\1\Data.   

    Are you trying to acquire data over a network?  What about anti-virus software?  

    I don't know the Chronos software or the settings.  In the Agilent CTC driver the Agilent Liquid Injection CTC cycle would be selected.  Could it be that it's not waiting for GC ready before initiating?   Is there an "overlap" or "prep ahead" selected?  GC method Post Run time?  What is your GC method's initial oven temperature and oven equilibration time?

  • The computer is stand-alone. Our data path is >40 characters and does include a blank space, so I will shorten the data path and omit the blank space.

    The method runs without overlap and the GC cycle time is sufficient to have the GC oven temperature back to initial temperature before the next injection is started. Oven initial temperature is 50°C, equilibration time 1 min and post run time 0 min.

  • On the GC, is the Not Ready LED lit?  If so, press the Status button and the GC will tell you what is not ready.

    Split or Splitless?  If it's Splitless the GC may need to be set to AutoPrepRun if the CTC sampler is not configured to send the prep run signal. The inlet must be set to splitless mode automatically. Make sure and have a Split method loaded as the last method in your sequence so that the inlet goes back to that mode.

    Auto Prep Run

    To set this parameter, usually for a non- Agilent integrator, workstation, or other controlling device:

    1 Press [Config] to view a list of configurable parameters.

    2 Scroll to Instrument and press [Enter].

    3 Scroll to Auto prep run and press [On/Yes]

    This information was found in the 7890B Advanced Operation Manual Page 40 and 41. 7890B_AdvOperationGuide.pdf (agilent.com)

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