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why the peak goes -ve initially

Posted: Sat Jul 28, 2007 5:16 am
by shullur
inj temp=270 degrees
fid temp=270 degrees
oven temp=100 degrees
with the above conditions on a gc i inject the methanol. the peak goes initially in the negative side before going +ve.

what may be the reason

Posted: Sat Jul 28, 2007 7:17 pm
by Bruce Hamilton
What carrier gas, detector, split injection ratios, how much injection etc etc.

Assuming FID, one likely cause is a large injection volume disturbing the FID, which can usually be fixed by adjusting detector gas flows, split vent, or injection volume.

Bruce Hamilton