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Artefact peak in RI chromatogram

Question asked by alexandre_mathieu on Jun 2, 2020
Latest reply on Jun 4, 2020 by zmb


I am working with a RI detector.(1200 agilent)

My eluant ist 800 MeOH, 100 Water, 100 0.1M ammonium acetate 

I have a problem at about 3 minutes. In some chromatograms, a peak is present but in other not. 


1: Blank

2: reference

3: sample 1 first preparation

4: sample 1. second preparation


I washed the system with IPA : no peak

I made injection of 10 blanks: no peak

10 injections of the sample: peak is present.


One of my hypothesis was a change in the eluant. The reinjection of the same vial over the time is leading to the same chromatogram.