植物油中甾醇烯类物质的检测研究

Determination of steradienes in vegetable oils

建立了GC-MS测定植物油中4种甾醇烯类物质的方法。样品用石油醚提取,经硅胶柱净化,HP-5毛细管柱(5%苯基聚硅氧烷,30 m)分离,质谱检测采用SIM模式。在0.062 5～1.0 mg/L的质量浓度范围内,峰面积与质量浓度呈良好线性,线性相关系数(r)大于0.99。在特级初榨橄榄油中添加0.025、0.050 mg/kg和0.100 mg/kg水平的甾醇烯类物质,平均加标回收率为78.6%～107.3%,相对标准偏差小于8%,方法检测限可达0.010 mg/kg。本方法准确、灵敏、可靠,已应用于实际样品分析,并可作为鉴别地沟油的方法之一。

A method for the determination of 4 steradienes in vegetable oils by GC - MS was established. Vegetable oil sample was extracted by petroleum ether, cleaned up by silica column, separated by HP- 5 column （5% phenyl polysiloxane, 30 m） and determined by mass spectrometry with SIM mode. The mass concentrations of steradicnes was between 0.062 5 mg/L and 1.0 mg/L, the calibration curve had good linear with correlation coefficients higher than 0.99. Extra virgin olive oils were added stcradienes 0.025, 0.050 mg/kg and 0. 100 mg/kg, the average recovery ranged from 78.6% to 107.3% , and the relative standard deviations （RSD） were less than 8%. The limits of detection could achieve 0.010 mg/ kg. This method was precise, sensitive and reliable, which had been applied to the practical sample analysis, and could be one of the methods to identify hogwash oil.