Leis H J, Leis M, Welz W, Malle E
Department of Mass Spectrometry, University Childrens Hospital, Graz, Austria.
J Chromatogr. 1990 Aug 3;529(2):299-308. doi: 10.1016/s0378-4347(00)83836-0.
A method for the quantitative measurement of captopril in human blood is described. Blood was immediately treated with N-ethylmaleimide to prevent oxidative degradation. The carboxyl moiety was derivatized to the pentafluorobenzyl ester, which shows excellent properties for negative-ion chemical ionization mass spectrometry. A stable isotope-labelled standard was prepared from the intact target molecule in quantitative yield by exchanging the oxygen atoms of the free carboxylic acid and the imide moiety against 18O. The detection limit under negative-ion chemical ionization conditions is ca. 100 times lower than under electron-impact or positive-ion chemical ionization conditions, therefore only very small amounts of the original sample have to be analysed. The method was applied to be quantitative determination of unchanged captopril in human plasma after oral administration of a 25-mg dose.
描述了一种定量测定人血液中卡托普利的方法。血液立即用N-乙基马来酰亚胺处理以防止氧化降解。羧基部分被衍生化为五氟苄酯，其在负离子化学电离质谱中显示出优异的性能。通过将游离羧酸和酰亚胺部分的氧原子与18O交换，以定量产率从完整的目标分子制备了稳定同位素标记的标准品。负离子化学电离条件下的检测限比电子轰击或正离子化学电离条件下低约100倍，因此只需分析极少量的原始样品。该方法用于口服25mg剂量后人体血浆中未变化的卡托普利的定量测定。
