Pentafluorobenzylation of capsaicinoids for gas chromatography with electron capture detection英文电子书.pdf

Journal of Chromatography, 457 (1988) 279-286 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands CHROM. 20 959 PENTAFLUOROBENZYLATION OF CAPSAICINOIDS FOR GAS CHROMA- TOGRAPHY WITH ELECTRON-CAPTURE DETECTION ANNA M. KRAJEWSKA* and JOHN J. POWERS Department of Food Science and Technology, University of Georgia, Athens, GA 30602 (U.S.A.) (First received June 9th, 1988;revised manuscript received August 17th, 1988) SUMMARY The alkylation of capsaicinoids with pentafluorobenzyl (PFB) bromide for gas chromatography with electron-capture detection was studied. The PFB derivatives were formed within 30 min at 60°C and did not show any signs of decomposition. The alkylated capsaicinoids had a hydrophobic character making them suitable for gas chromatography on a non-polar column. The electron-capture response for the PFB derivatives of capsaicinoids was very sensitive and amounts of capsaicin down to 10 pg were easily detected. The method was succesfully applied to measurement of cap- saicinoids in Capsicum products using vanillylamide of octanoic acid as an internal standard. INTRODUCTION Due to growing interest in the pharmacological actions of capsaicin and its analogues called capsaicinoids1-3, there is a need for sensitive and accurate analytical methods for their detection. Colorimetric4, direct and differential spectrophotomet- rig?, thin-layer and paper chromatographic7v8 methods can be used only for the analysis of total capsaicinoids. Gas chromatography (GC)‘*“, high-performance liq- uid