反相聚合物固相萃取-气相色谱-质谱法测定植物油中角鲨烯和四种植物甾醇

该文建立了基于反相聚合物为填料,固相萃取-气相色谱-质谱法准确测定植物油中角鲨烯和4种植物甾醇的快速分析方法。植物油样品经2 mol/L氢氧化钾-甲醇皂化,采用聚合物反相固相萃取小柱Oasis HLB净化,后经HP-5毛细管色谱柱(30 m×0.25 mm×0.25μm)分离,气相色谱-质谱仪检测,分别以角鲨烷和5α-胆甾烷-3β-醇作为内标进行定量分析。结果表明,角鲨烯和4种植物甾醇在各自的浓度范围内线性关系良好,相关系数均大于0.998,加标浓度为50、250、500 mg/kg时,方法的平均回收率为91%~107%,相对标准偏差分别为1.2%~7.2%,方法的检出限为0.30~5.87 mg/kg。该方法样品前处理简单快速,背景干扰低、灵敏度高、重现性好、回收率高,适用于食用植物油中角鲨烯和4种植物甾醇的准确定量分析。

Determination of squalene and four phytosterols in vegetable oil by polymeric reversed solid phase extraction coupled with GC-MS

A novel,simple and rapid method for the determination of squalene and four phytosterols in vegetable oil was developed by using polymeric reversed solid-phase extraction and gas chromatography-mass spectrometry(SPE-GC-MS).The samples were saponified by 2 mol/L solution of KOH in methanol,purified by a polymeric reversed(Oasis HLB)cartridge,and separated by HP-5 capillary chromatographic column(30 m×0.25 mm×0.25μm).The analytes were analyzed by GC-MS under selected ion monitoring(SIM)mode,and the quantitative analysis was carried out by the internal standard method with squalane and 5α-Cholestan-3β-ol.The results indicated that there were good linear relationships in corresponding mass concentration ranges of the squalene and four sterols,the correlation coefficients were all higher than 0.998.The recoveries ranged from 91%to 107%and the relative standard deviations(RSDs)were from 1.2%to 7.2%at the spiked levels of 50、250 and 500 mg/kg.The detection limits were 0.30 to 5.87 mg/kg.The proposed method is simple and rapid with high sensitivity,high recovery and good precision,suitable for determination of squalene and four phytosterols in vegetable oil.