Kock R, Delvoux B, Greiling H
Institute for Clinical Chemistry and Pathobiochemistry, Medical Faculty, University of Technology Aachen, Germany.
Clin Chem. 1997 Oct;43(10):1896-903.
We have developed a liquid chromatography-isotope dilution mass spectrometry procedure to quantify total cholesterol in serum. A particle-beam interface was used for coupling the liquid chromatograph and the mass spectrometer. After electron impact ionization the ions m/z = 386 and m/z = 389 were used for selective ion monitoring of cholesterol and the internal standard [25,26,27-(13)C]cholesterol. The sample preparation steps required for serum materials are alkaline hydrolysis and an extraction of the cholesterol into the cyclohexane phase. Imprecision for the determination of cholesterol in control materials is typically <1.0%. The deviation from the certified reference values was <0.75% for all control materials tested. A method comparison of the results obtained by this method with those obtained by gas chromatography-isotope dilution mass spectrometry for n = 28 pooled human sera derived from samples analyzed in our routine laboratory did not show differences >2.5%.
我们开发了一种液相色谱-同位素稀释质谱法来定量血清中的总胆固醇。使用粒子束接口将液相色谱仪与质谱仪联用。电子轰击电离后，m/z = 386和m/z = 389的离子用于选择性离子监测胆固醇和内标[25,26,27-(13)C]胆固醇。血清样本所需的制备步骤为碱性水解以及将胆固醇萃取到环己烷相中。对照品中胆固醇测定的不精密度通常<1.0%。所有测试的对照品与认证参考值的偏差<0.75%。对于我们常规实验室分析的n = 28份混合人血清样本，该方法所得结果与气相色谱-同位素稀释质谱法所得结果的方法比较显示差异>2.5%。
