裂解色谱法甲基化试剂碱性对多不饱和脂肪酸降解和异构化的影响  

The Effect of Alkalinity of Methylation Reagent on Isomerization and Degradation of Polyunsaturated Fatty Acids with Pyrolysis Gas Chromatography

作　　者：丁军凯[1,2] 荆伟 邹天治[1,2] 宋鸣 喻晓光[1,2] 范垂昌 

机构地区：[1]辽宁省刑事科学技术研究所 [2]中国医科大学法医学系

出　　处：《色谱》1997年第1期70-72,共3页Chinese Journal of Chromatography

基　　金：1995年公安部部级课题并获基金

摘　　要：采用最佳比例裂解甲基化试剂，消除了强碱性甲基化试剂对油脂中多不饱和脂肪酸降解和异构化作用的影响。Simultaneous pyrolysis and methylation gas chromatography(SPM GC) is a fast analytical method which was developed in recent years. However, the strong alkalinity of tetramethylammonium hydroxide(TMAH) may result in the isomerization and degradation of polyunsaturated fatty acids in oils and fats during analysis. This paper describes the application of SPM GC to polyunsaturated fatty acids in soybean oil and the isomerization and degradation may be prevented by choosing the optimum proportion of TMAH to methanol which is 1∶50(pH 8 8). With this chosen optimum proportion there were no detectable isomerized and degraded peaks in the chromatograms. Pyrograms were obtained by interfacing a Curie point pyrolyser to a Shimadzu GC 14A gas chromatograph equipped with a flame ionisation detector. A capillary column(FFAP) was used. All of the pyrolysis products were identified by mass spectrometry which was carried out with a Varian 3400 gas chromatograph interfaced to a Finnigan SSQ 710 mass spectrometer using electron impact ionisation(70eV). This method is simpler and more convenient than both the methods “neutralization of acid” and “simultaneous injection of the sample and a short chain fatty acid methylester” reported in the previouns papers .

关 键 词：多不饱和脂肪酸 甲基化试剂 裂解色谱法 异构化 

分 类 号：O623.61[理学—有机化学] O657.7[理学—化学]