Capsaicin by FID GC

[macamo]

How do you analyze the capsaicin with GC-FID?. Is It necessary to hava a derivatization?

[chromatographer1]

Published articles have used TMS derivatives when analyzed by GLC.

My experience was that underivatized capsaicin was unstable at temperatures required to elute it from thin film capillary columns.

You may wish to try a mild reagent like HMDS alone unless you find a suitable reference procedure.

I have found that the common impurities were best separated by RP-HPLC.

best wishes,

Rod

[MSCHemist]

I prefer to do capsaicinoids/Scoville heat units via GC/MS. The EI spectra for them are are pretty much a base 137 benzyl fragment and a smaller molecular ion. I use the ASTA method with an additional step of blowing down the ethanol and redissolving in toluene with octacosane ITSD. I inject with a slow ramp from 220 to 280 on a 1701 column 280 inlet temp 10:1 split. Using a SIM program I get a LOQ of below 1 ppm. It matches fairly well with HPLC though nonivamide and capsaicin coelute using HPLC.

I find no derivatization is necessary.