Hi!

First: My english is not as good as it should be ... so sorry for that!

My problem is the identification of Capsaicin with a GC.
I soluted the Capsaicin with EtOH and try to detect it with a PE-8500 Series GC with a Poly(94%-methyl-5%-phenyl-1%-vinyl)-siloxan column (50 m; 0,32 diameter) and a FID. The carrer gas is N2. The parameters for the detection are the following:

Injector temperature : 280°C
Detector temperature : 300°C
Split : 1:40
Carrier gas flow : 1.5 ml/min
Oven temp. 1 : 220°C
Hold time : 1 minute
Ramp rate 1 : 3°C / min
Oven temp. 2 : 250°C
Hold time 2 : 4 minutes

Now the problem: I just get one (!) peak after about 3.5 minutes and that is the one for the EtOH.

If anyone could tell me whats wrong I would be thankful to read it!

There are applications in the literature demonstrating this analysis using LC. Michael Dong from PerkinElmer published an LC application paper on this analysis using LC a few years ago.

I have done the analysis for Capsaisin using LC and GC while at Sigma Chemical about 1984. The LC is very elegant but the Gc is quicker and cheaper.
I believe you should not use Ethanol for this analysis. I would suggest that you derivatize Capsaisin in a proper silylating reagent and test on the 5% Phenyl column you are using, or a VOCOL column, or 50% Phenyl Methyl silicone. Be aware that this amide is not stable in a reagent, but it is OK for a quick determination. LC will do a better job of separating the saturated homolog and various isomers. I agree w/ anon. that LC is a better solution. Good luck.
Rod

Thanks a lot for your answers! I'll try the more polar column and the derivatisation first.

I think that the American Spice Trade Association has a method for the capsaicins. They do have a compendia of methods.