市售橄榄油豆甾二烯与脂肪酸烷基酯含量分析

Determination of stigmastadiene and fatty acid alkyl esters in commercial olive oil

建立了一种前处理简便快速的橄榄油中豆甾二烯含量测定方法,结合橄榄油中脂肪酸烷基酯的检测,对市售不同标称等级的橄榄油样品进行分析。结果表明,橄榄油样品加入内标后用正己烷溶解,商品化硅胶柱净化,正己烷洗脱,DB-5MS色谱柱进行分离,选择离子监测模式采集,内标法定量对豆甾二烯含量进行GC-MS测定。豆甾二烯的检出限为0.05 mg/kg,定量限为0.10 mg/kg,在0.05~2.0μg/mL质量浓度范围内具有良好的线性关系,回收率为98.05%~100.19%,RSD为0.54%~3.04%。不同标称等级橄榄油中豆甾二烯与脂肪酸烷基酯含量差异较大,两者联用可以更好地用于特级初榨橄榄油品质与掺伪鉴别。

A method with simple and rapid pretreatment for the determination of stigmasterodiene content in olive oil was established, and combining with the determination of fatty acid alkyl esters in olive oil, the commercial olive oil samples of different grades were analyzed. The results showed that the sample was dissolved with n-hexane after adding the internal standard, and cleaned up on a commercial silica gel column. And then it was separated by DB-5 MS chromatographic column and analyzed by GC-MS in selected ion monitoring mode to determine the stigmasterodiene content. The detection limit and quantification limit of stigmasterodiene were 0.05, 0.10 mg/kg, and there was a good linear relationship in the range of 0.05-2.0 μg/mL. The rate of recovery was 98.05%-100.19%, with RSD of 0.54%-3.04%. The contents of stigmadiene and fatty acid alkyl esters had significant differences in different grades olive oils, and the combined detection of them had important reference value in the identification of the quality and adulteration of extra virgin olive oil.