Butyl Carbitol on a FAME Wax Column

[EsterCorrGC]

We are having trouble when analyzing the alcohol content (butyl carbitol) of Butyl Carbitol Stearate. When injecting the same sample multiple times the area percent of the alcohol will vary between 1 - 2%. I have checked all the usual suspects: septa, pressure, liner. Does anyone know if the column or other interactions could be accounting for the molecules to be retained somewhere?

[Consumer Products Guy]

We always assayed alcohols and carbitols with more than 3 carbons by using DMF as solvent, derivatizing with BSTFA, and assay on a nonpolar capillary like DB-5.

[EsterCorrGC]

All of our products are run neat. With the exception of a few methylated raw materials (Fatty Acids). I have set up the inlet with a split and we only inject 1ul of the butyl carbitol stearate.

We use the GC as a more accurate measurement of the residual alcohol for in-process samples while the plant is steam stripping the OH out. We went to this method because we don't get accurate numbers from the titration method. But lately we are seeing that duplicate injections are not coming out the same.