SPME-GC-MS with CombiPAL sampler

[kvaak]

I'm having some problems with CombiPAL sampler for doing SPME runs. The SPME part is doing fine, and the results are good. The problem is that when I place the GC cycle as the GC run time + cooling down, the sampler starts to preheat the sample after that, not before. So If I'm having 30min preheating and 30min extraction, and after that 42min analysis time, the sampler should start to heat new sample after ??? minutes. However it starts to heat the sample after 42min.

I would really appreciate any helps!

regars,
kvaak

[Ron]

Are you using Cycle Composer software, or controlling from the handheld controller? Not all versions of Cycle Composer allow you to do heat ahead, the software runs one line at a time and one line must be finished before the next one starts.

[kvaak]

Have anyone had same problems, that I am having with Combi-Pal sampler?

I have been doing headspace and SPME analysis. The analysis are going fine, so that part is not the problem.

Eith headspace method I have been using PAL injector cycle overlapping with good success. So that after PAL has injected, it starts to incubate the next sample after 11mins (incubation time 10min, GC run time 20min). And after the first run is finished, the sampler is ready to inject next sample.

I have tried to do the same with SPME method, but somehow it's not working. Somehow PAL does'n understand that it should inject also the next sample. So PAL incubates the first sample and injectes it, starts to incubate next sample, but never inject it? If I get this to work, I can anayze much more in one day, since in my method preincubation time is 30mins, and incubation with fiber is 60mins, and the GC run time is 42 min. Could it work, if I "change" the GC run time in PAL cycle to be only a short time such as 2mins. Would it after that start to preincubate the next one.

Am I doing sometihin wrong, or is it just in my head

I would really apprecciate any comments!!!

[Schmitty]

I would try different setups and see if it works, if you have extra time to mess around with it and still get the samples done that you need to get done.

Also, you may want to update the firmware on the PAL or double check the wiring on the trigger. The Autosampler may not be getting a ready signal, or it may be waiting for the ready signal, which only comes after teh GC has cooled down.

Where are you located? I've found that GerstelUS is more than willing to help troubleshoot over the phone or make a visit. Also, LEAP Technologies is helpful.

You didn't reply to the question of whether you were using software to run the PAL or the handpad.

Regards

[kvaak]

I am using the PAL with MS Chemstation.
I will try to update my firmware, since I think I have been getting sometimes some error messages related to firmware.
Unfortunately, I'm located in Europe, but I will contact to our local sales to get it working. I would really help me a lot to be able to analyze more samples in one day.