色谱2016，Vol.34Issue(4)：429-435,7.DOI:10.3724/SP.J.1123.2015.12016
两种离子化技术气相色谱-质谱法测定橄榄油中甾醇烯类物质的比较
A comparative study of two ionization techniques in gas chromatography-mass spectrometric determination of sterenes in olive oil
摘要
Abstract
The gas chromatography-mass spectrometric( GC-MS ) method with two different ionization techniques,electron impact( EI)and positive chemical ionization( PCI),have been developed for the simultaneous determination of three sterenes in olive oil. The olive oil sample was dissolved in petroleum ether,followed by cleanup on a silica gel column and finally ana-lyzed by GC-EI/MS and GC-PCI/MS in selected ion monitoring mode. The quantitation was per-formed by internal standard calibration with cholesta-3,5-diene as internal standard. These two methods were compared in terms of linearity,accuracy,precision and sensitivity. Good lineari-ties were obtained with correlation coefficients( r)higher than 0. 999 for campesta-3,5-diene in the range of 0. 024 to 0. 48 mg/L,stigmasta-3,5,22-triene in the range of 0. 02 to 0. 50 mg/L and stigmasta-3,5-diene in the range of 0. 03 to 0. 75 mg/L. The accuracy test was carried out at three spiked levels in extra virgin olive oil. The average recoveries ranged from 88. 7% to 99. 5%(EI)and 87. 1% to 109. 2%(PCI),with relative standard deviations(RSDs,n=6)not higher than 8. 3%. Limits of quantification( LOQs,S/N=10)were 0. 03 mg/kg( EI)and 0. 03-0. 10 mg/kg( PCI). Comparative analysis showed a large number of fragment ions could be obtained in EI mode while quasi-molecular ions or other adduct molecular ions were the most abundant ion formed in the PCI mode. Besides,PCI has a better selectivity than EI when applied to real samples. In conclusion,these two ionization techniques are complementary and alternative in the routine analysis of sterenes in olive oil.关键词
气相色谱-质谱/甾醇烯/电子轰击电离/正化学电离Key words
gas chromatography-mass spectrometry ( GC-MS )/sterenes/electron impact ionization( EI)/positive chemical ionization( PCI)分类
化学引用本文复制引用
魏雪缘,邓晓军,王岁楼,沈伟健,余可垚,张建,陆慧媛,吴斌,沈崇钰,赵增运,柳菡..两种离子化技术气相色谱-质谱法测定橄榄油中甾醇烯类物质的比较[J].色谱,2016,34(4):429-435,7.基金项目
国家质检总局科技计划项目（2015IK141）；江苏省“333工程”项目（ BRA2014330）；上海长三角科技合作项目（15395810100）．@@@@Science and Technology Project of AQSIQ（ No．2015IK141）；“333 Project”of Jiangsu Province（ No． BRA2014330）；Science and Technology Project of Shanghai Yangtze River Delta（ No．15395810100）． （）
