Page 1 of 1
negative peaks HPLC
Posted: Mon Apr 07, 2008 4:15 pm
by Yata
I have a problems with negative peaks. My systems is a gel permeation column with THF- methanol as solvent, I'm separating glicerol, triglicerides and ethyl esthers with an RI detector.
Posted: Fri Apr 11, 2008 2:42 am
by tom jupille
Can you be a bit more specific? Where do these peaks occur relative to your analytes? Are they always at the same retention times or do they move around?
Posted: Fri Apr 11, 2008 3:14 am
by Kostas Petritis
Generally speaking, if your samples contain compounds/solvents that have a refractive index lower than the refractive index of your mobile phase (i.e. TFA-methanol) then you will experience negative peaks when these compounds/solvents are eluted...