提出了食用植物油中胆固醇的超高效液相色谱-串联质谱测定方法。食用植物油经皂化后用石油醚-乙醚(1+1)溶液提取,以Waters ACQUITY UPLC BEH C18色谱柱(50 mm×2.1 mm,5 μm)为分离柱,以甲酸-甲醇(0.1+99.9)溶液为流动相,以2,2,3,4,4,6-d6胆固醇为内标,采用大气压化学电离源在多反应监测负离子模式下进行测定,胆固醇和内标的定量离子对分别为m/z 369.2/146.9,369.2/160.9和375.2/166.5。胆固醇在0.1~5 mg·L-1范围内呈线性,测定下限(10S/N)为0.02 ng。在3个浓度水平上对方法做回收试验,测得回收率在102%~110%之间。

A method for the determination of cholesterol in edible vegetable oil by ultra-high-performance liquid chromatography hyphenated with tandem mass spectrometry (HPLC-MS/MS) was proposed. Cholesterol in samples was extracted with a mixture of petroleum ether and ethyl ether (1+1). The eluate was used for UHPLC-MS/MS determination, in which the ACQUITY UPLC BEH C18 column (50 mm×2.1 mm, 5 μm) was used as separation column, a mixture of formic acid and methanol (0.1+99.9) was used as mobile phase, and 2,2,3,4,4,6-d6-cholesterol was used as internal standard. Atmospheric pressure chemical electrospray ionization under the mode of multiple reaction monitoring was used in the detection. Ion pairs used for the quantitative analysis were m/z 369.2/146.9, 369.2/160.9 for cholesterol and m/z 375.2/166.5 for internal standard. Linearity range was found between 0.1-5 mg·L-1, and lower limit of determination (10S/N) found was 0.02 ng. Recovery was tested at 3 concentration levels, giving results of recovery ranged from 102% to 110%.