反相高效液相色谱法同时测定植物油中四种生育酚

摘要

建立了反相液相色谱法同时测定植物油中4种生育酚的方法.样品用甲醇超声提取,离心后取上清液氮吹至干,甲醇定容后过有机相滤膜,反相C30柱(4.6 mm i.d.×250 mm,5 μm)分离,甲醇-水-叔丁基甲醚(60∶15∶25)作流动相等度洗脱,荧光检测(λex=290 nm,λem=340 nm).结果表明,4种生育酚的质量浓度在0.050～100.0 mg/L范围内与峰面积呈良好的线性关系,线性相关系数(r2)大于0.999.在加标水平为0.50、50.0、500.0 mg/kg时,4种生育酚的平均加标回收率为81.3％ ～93.2％,相对标准偏差(RSD)小于6％,α-生育酚、β-生育酚、γ-生育酚及δ-生育酚的方法检出限(LOD)分别为0.10、0.05、0.05、0.02mg/kg.方法准确、灵敏、可靠,可应用于实际样品的分析.%A method for the simultaneous determination of four tocopherols in vegetable oils by reverse phase high performance liquid chromatography(RP-HPLC) was established.The sample was extracted with methanol under ultrasonic.The chromatographic separation was carried out on a C30 column(4.6 mm i.d.×250 mm,5 μm) using fluorescence detection at 290 nm of excitation wavelength and 340 nm of emission wavelength.Methanol-water-tert-butyl methyl ether(60 ∶ 15 ∶ 25)was used as mobile phase by isocratic elution.Results showed that good linear ranges for 4 tocopherols were obtained from 0.050 mg/L to 100.0 mg/L with correlation coefficients (r2) larger than 0.999.The mean recoveries were in the range of 81.3％-93.2％ at three spiked levels of 0.50,50.0,500.0 mg/kg,and the relative standard deviations(RSDs) were less than 6％.The limits of detection(LODs) were 0.10 mg/kg for α-tocopherol,0.05 mg/kg for β-and γ-tocopherol,and 0.02 mg/kg for δ-tocopherol.The method is accurate,sensitive and reliable,and could be applied in the real sample analysis.