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stick like GC chromatograms
Posted: Mon Oct 19, 2009 9:26 am
by PHchrom
Dear All,
We are using Agilent 6890 gas chromatograph and agilent mass detector for a halogenated monoterpene study. After a few runs, the GC-MS gave stick-like chromatograms. The image of the chromatogram is here: [/img]
http://studwww.ugent.be/~dpayo/bad_chrom.jpg
On the lower left is a closer view of one peak and on the lower right is the mass spectrum.What could be the problem? The person assisting me could not explain why. If I need to provide some more details to help diagnose the problem, let me know.
Thanks for any help.
DPayo
Posted: Mon Oct 19, 2009 10:36 am
by bhuvfe
Dpayo,
I cannot see the image.
Does your MS pass the tune?
Regards,
bhuvfe
Re: stick like GC chromatograms
Posted: Mon Oct 19, 2009 2:04 pm
by thohry
Dear All,
We are using Agilent 6890 gas chromatograph and agilent mass detector for a halogenated monoterpene study. After a few runs, the GC-MS gave stick-like chromatograms. The image of the chromatogram is here: [/img]
http://studwww.ugent.be/~dpayo/bad_chrom.jpg
On the lower left is a closer view of one peak and on the lower right is the mass spectrum.What could be the problem? The person assisting me could not explain why. If I need to provide some more details to help diagnose the problem, let me know.
Thanks for any help.
DPayo
I can not see the chromatogram neither. Anyway, you can check the ion source. Maybe the sample is not clean and it messed the source. I just guess.
Posted: Mon Oct 19, 2009 2:40 pm
by PHchrom
Dpayo,
I cannot see the image.
Does your MS pass the tune?
Regards,
bhuvfe
Thanks for the reply, Bhuvfe and thohry.
I was just informed that the MS filament needs to be changed.
I noticed that the link only works with Firefox.
Posted: Mon Oct 19, 2009 3:02 pm
by bhuvfe
I could see indeed the image with firefox.
What you see is mainly noise. Do an autotune and see what happens (and maybe switch to the other filament)
You can get a similar "chromatogram" with a very low voltage on the electron
multiplier.
Posted: Mon Oct 19, 2009 3:36 pm
by PHchrom
I could see indeed the image with firefox.
What you see is mainly noise. Do an autotune and see what happens (and maybe switch to the other filament)
You can get a similar "chromatogram" with a very low voltage on the electron
multiplier.
Bhuvfe,
Thanks for the info. I'll discuss this with the technician helping me. I'm just starting to learn this instrument.
