Has anyone done surfactant analysis using HPLC -RI

Question

I want to analyze non-ionic surfactant (fatty alcohol ethoxylate and tallowamine ethoxylate ) in a formulation. I tried C18 column with 80:20 Methanol: water combination but I am not getting proper peaks. Due to branched alchol I am getting humps in the chromatogram. Can anyone suggest how to go forward with RI detector as we do not have ELSD detector.

Dr. Know · Accepted Answer

Hi, 
 it all depends on the size of your ethoxylates and the pore size of the column. Normally SEC columns are used for this type of analyses. Check these application notes: 
 5991-5795EN = https://www.agilent.com/cs/library/applications/5991-5795EN.pdf 5990-8311EN = https://www.agilent.com/cs/library/applications/5990-8311EN.pdf 
 Regards, 
 Norbert