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Small peak of the solvent

Posted: Wed May 14, 2008 11:41 pm
by kankyo
Hello,

I am running a GC of my kerosene samples in CS2. The kerosene concentration is 2% w/v in CS2. The peak of CS2 however, is very small almost half that of the highest peak of the hydrocarbon component of kerosene. I have not encountered this result in my previous runs. Is this a problem? CS2 which is present in higher amount and is supposed to yield an enormous peak.

My GC conditions are the following:
oven program: 30C for 4 min, 10C/min to 260C
Injector at 325C
Detector at 350C
The column is an Inert CAP of GL Sciences with an ID of 0.25 mm length of 30 m, df of 0.25
Im using Gas Chro 4000 of GL sciences

Posted: Thu May 15, 2008 2:36 am
by Suresh Seethapathy
FID has very low response to CS2. The FID response is more sensitive to compounds containing C-H bonds. What you are observing is right and we use CS2 as solvent in many of our analysis for just that reason.. On the other hand, you cannot use CS2 as solvent when using ECD detector because of very high response which might temperorily create ECD response problem.

Cheers!
Suresh.

Posted: Thu May 15, 2008 6:22 am
by kankyo
Thanks