stick like GC chromatograms

[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

[bhuvfe]

Dpayo,

I cannot see the image.

Does your MS pass the tune?

Regards,
bhuvfe

[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.

[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.

[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.

[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.