气相色谱-质谱法测定食用植物油中多种植物甾醇含量

Determination of Various Phytosterols in Edible Vegetable Oils by Gas Chromatography-mass Spectrometry

[目的]建立气相色谱-质谱法(GC-MS)同时测定食用油中β-谷甾醇、豆甾醇、菜油甾醇、菜籽甾醇含量的方法。[方法]样品选用氢氧化钾-乙醇皂化、正己烷萃取、浓缩、衍生化后以正己烷定容,采用GC-MS选择离子扫描模式(SIM),外标法定量。[结果]β-谷甾醇、豆甾醇、菜籽甾醇的线性范围为5~500μg/mL,菜油甾醇的线性范围为2.5~250.0μg/mL,线性相关系数(R^(2))均大于0.999,检出限为0.05~0.10 mg/kg,定量限为0.1~0.3 mg/kg,加标回收率为80.5%~107.8%,相对标准偏差(RSD)为2.3%~9.8%。[结论]该方法操作简单、高效、灵敏度高、重复性好,适用于食用植物油样品中β-谷甾醇、豆甾醇、菜油甾醇、菜籽甾醇含量的测定。

[Objective]A method for simultaneous determination ofβ-sitosterol,stigmasterol,campesterol and brassicasterol in edible oil was established by gas chromatography-mass(GC-MS).[Method]Sample was saponified by potassium hydroxide-ethanol solution,n-hexane extraction,concentration,derivatization,and then diluted with n-hexane.GC-MS was used to select ion scanning mode(SIM)and external standard method was used for quantification.[Result]There were good linear relationships forβ-sitosterol,stigmasterol,brassicasterol in 5-500μg/mL,and campesterol in 2.5-250.0μg/mL,respectively.Linear correlation coefficients(R^(2))were greater than 0.999.Limits of detection were 0.05-0.10 mg/kg and limits of quantification were 0.1-0.3 mg/kg,respectively.Adding standard recovery rate was 80.5%-107.8%,relative standard deviation(RSD)was 2.3%-9.8%.[Conclusion]This method is easy to operate,efficient,highly sensitive,and has good repeatability,which is suitable for the determination ofβ-sitosterol,stigmasterol,campesterol and brassicasterol contents in edible vegetable oil samples.