Takatsu A, Nishi S
Clin Chem. 1987 Jul;33(7):1113-7.
We describe an accurate, precise method for determination of total serum cholesterol by isotope dilution/mass spectrometry (IDMS) with liquid-chromatographic separation. After adding [3,4-13C]cholesterol to serum and hydrolyzing the cholesterol esters, we extract the total cholesterol. "High-performance" liquid chromatography (HPLC) is used to separate the extracted cholesterol for measurement by electron-impact mass spectrometry with use of a direct-insertion device. To evaluate the specificity and the accuracy of this method, we also studied the conventional IDMS method, which involves converting cholesterol to the trimethylsilyl ether and assay by gas chromatography-mass spectrometry with use of a capillary column. The coefficient of variation for the HPLC method was a little larger than that for the conventional method, but mean values by each method agreed within 1% for all sera tested.
我们描述了一种通过液相色谱分离的同位素稀释/质谱法（IDMS）测定血清总胆固醇的准确、精密方法。向血清中加入[3,4-13C]胆固醇并水解胆固醇酯后，我们提取总胆固醇。使用“高效”液相色谱（HPLC）分离提取的胆固醇，通过使用直接进样装置的电子轰击质谱进行测量。为评估该方法的特异性和准确性，我们还研究了传统的IDMS方法，该方法涉及将胆固醇转化为三甲基硅醚并通过使用毛细管柱的气相色谱-质谱法进行测定。HPLC方法的变异系数略大于传统方法，但两种方法对所有测试血清的平均值在1%以内一致。
