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!
By Anonymous on Wednesday, July 24, 2002 - 02:29 pm:
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.
By Anonymous on Wednesday, July 24, 2002 - 03:04 pm:
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.
By Anonymous on Thursday, July 25, 2002 - 12:06 am:
Thanks a lot for your answers! I'll try the more polar column and the derivatisation first.
By chris on Wednesday, July 31, 2002 - 11:51 pm:
I think that the American Spice Trade Association has a method for the capsaicins. They do have a compendia of methods.
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