采用固相萃取-液相色谱-串联质谱法测定动植物油脂中胆固醇的含量。样品在无水乙醇和氢氧化钾溶液中皂化，用石油醚-乙醚（1+1）混合液提取，经硅胶固相萃取柱净化。以Zorbox SB C₁₈色谱柱为分离柱，以不同体积比的5 mmol·L^-1乙酸铵溶液和乙腈-甲醇（1+1）溶液的混合液为流动相进行梯度洗脱，采用电喷雾正离子源和多反应监测模式检测。采用内标法定量，胆固醇的质量浓度在0.1~5.0 mg·L^-1内与其对应的峰面积呈线性关系，胆固醇在植物油脂和动物油脂中的检出限（3S/N）分别为0.02，0.2 mg·kg^-1。在0.5，1.0，5.0 mg·kg^-1等3个浓度水平进行加标回收试验，回收率为85.2%~92.0%，测定值的相对标准偏差（n=6）为3.6%~9.4%。

LC-MS/MS was applied to the determination of cholesterol in fats or oils of animals or vegetables with solid phase extraction. The sample was saponified by ethanol and potassium hydroxide, and extracted with mixture of petroleum ether and ethyl ether(1+1), and then purified by silica gel solid phase extraction column. Zorbox SB C₁₈ chromatographic column was used as stationary phase, and the mixture of 5 mmol·L^-1 ammonium acetate solution and acetonitrile-methanol(1+1) solution mixed in different ratios was used as mobile phase in gradient elution. ESI⁺ and multi-reactions monitor mode were adopted in MS/MS. Internal standard method was used for quantitative. Linear relationship between values of peak area and mass concentration of cholesterol was kept in the range of 0.1-5.0 mg·L^-1, with detection limits (3S/N) of cholesterol in fats or oils of vegetables or fats or oils of animals of 0.02, 0.2 mg·kg^-1, respectively. Tests for recovery were made by standard addition method at the concentration levels of 0.5,1.0,5.0 mg·kg^-1, giving values of recovery and RSD's (n=6) in the ranges of 85.2%-92.0% and 3.6%-9.4% respectively.