【摘要】 目的建立同位素稀释液相色谱串联质谱（LC/MS/MS）测定血清总胆固醇的方法。方法血清样品中加入[3,4-¹³C₂]-胆固醇作内标,用氢氧化钠水解血清胆固醇酯为胆固醇,用三氧化铬-硫酸氧化胆固醇为胆甾-4-烯-3,6-二酮,用 LC/MS/MS 分析胆固醇氧化产物,采用大气压化学电离源,用多反应监测（MRM）模式和选择离子监测（SIR）模式检测,用修正标准曲线法对血清样品进行定量。结果两种检测模式的峰面积比与胆固醇浓度的线性相关系数均大于0.999 9。MRM 模式测定血清总胆固醇的平均批内变异系数（CV）为0.95%（范围0.92%～0.99%）,平均总 CV 为0.86%（0.82%～0.89%）;SIR 模式平均批内 CV 为0.64%（0.54%～0.77%）,平均总 CV 为0.69%（0.62%～0.81%）。测定国际或国家标准物质结果与靶值的平均偏差在 MRM 模式下为0.23%（0.14%～1.00%）,SIR 模式为0.24%（0.07%～1.27%）。结论成功建立了 LC/MS/MS 测定血清总胆固醇的方法,方法特异、精密、简便,可望用作血清胆固醇测定的参考方法。更多还原

【Abstract】 Objective To develop a method for the determination of total cholesterol in serum by isotope dilution liquid chromatography tandem mass spectrometry （ID-LC/MS/MS）.Methods Serum samples were supplemented by addition of [3,4-¹³C₂]-cholesterol,hydrolyzed with alcoholic sodium hydroxide and oxidized into cholest-4-ene-3,6-dione by chromic acid.The oxidation products were analyzed by LC/MS/MS using atmospheric pressure chemical ionization （APCI） source and detection modes of multiple reaction monitoring （MRM） and single ion recording （SIR）.Signals （peak areas） of the internal standard were corrected for the contributions of cholesterol and the signal ratios of cholesterol to internal standard for the calibrations were linearly regressed against cholesterol concentrations.The resulted regression equation was used for the calculation of serum cholesterol concentrations.Results The correlation coefficients between the peak area ratios and cholesterol concentrations were 0.999 9 and higher.Under MRM mode,the average within-run CV of the results obtained on 3 serum samples was 0.95% （ranged from 0.92% to 0.99%） and the total CVwas 0.86% （0.82% to 0.89%）,and under SIR mode,the within-run CV was 0.64% （from 0.54% to 0.77%） and the total CVwas O.69% （0.62% to 0.81%）,respectively. Results on certified reference materials （SRM 1951 a Level Ⅰ and Level Ⅱ;GBW 09145 and GBW 09147） showed an average bias of 0.23% （0.14% to 1.00%） under MRM mode,and 0.24% （0.07% to 1.27%） under SIR mode.Conclusions An ID-LC/MS/MS method for serum cholesterol has been developed.It is specific and precise and may be used as a candidate reference method.更多还原