顶空GC-MS法测定植物油中的6种挥发性苯系物

建立了植物油中6种挥发性苯系物的静态顶空气相色谱-质谱测定方法。植物油样品在80℃温度下平衡30min,顶部气体采用气相色谱-质谱方法测定,程序升温,HP-INNOWAX柱分离,以EI离子源电离,选择离子监测模式(SIM)定性,外标法定量。六种挥发性苯系物在0.1～5μg/g范围内线性良好,相关系数(r2)为0.9910～0.9996,方法检出限(S/N=3):苯为0.006μg/g,甲苯为0.012μg/g,乙苯0.015μg/g,对二甲苯、邻二甲苯、间二甲苯0.03μg/g;添加水平在0.1～0.5μg/g时,回收率为79.46%～103.38%,RSD=2.34%～8.76%(n=6)。

Determination of 6 kinds of volatile benzene in vegetable oil by headspace GC-MS

A method was developed for quantitative determination of 6 volatile benzenes in vegetable oil.Sample of vegetable oil was counterpoised for 30min in 80℃.Gas of headspace was determined by GC-MS.Column was risen by temperature programmed(TP).The analytes were separated on a HP-INNOWAX column.The separated compounds were ionized by EI,analyzed in selective ion monitoring(SIM) mode and quantified using the external standard method.The calibration curves were linear in the range of 0.1~5 g/g with the correlation coefficients(r2) of 0.9910～0.9996.The methodological limits detection(S/N=3) of benzene was 0.006 g/g,toluene was 0.012 g/g,ethanol was 0.015 g/g,and xylenes was 0.03 g/g.The recoveries was 79.46%~103.38% with the relative standard deviations(RSD%) of 2.34%~8.76%(n=6) at the spiked levels of 0.1~0.5 g/g.