Edlund O, Bowers L, Henion J, Covey T R
New York State College of Veterinary Medicine, Cornell University, Ithaca 14850.
J Chromatogr. 1989 Dec 29;497:49-57. doi: 10.1016/0378-4347(89)80004-0.
Urine samples were spiked with [17-methyl-2H3]methandrostenolone as internal standard and extracted with a mixture of dichloromethane and cyclohexane. The organic phase was concentrated and injected onto a short octyl-silica column (30 mm x 4.6 mm I.D.) for separation of methandrostenolone and 17-epimethandrostenolone. The effluent from the column was connected to a Sciex TAGA 6000E triple quadrupole mass spectrometer equipped with an atmospheric pressure ion source for sampling of ions generated by a heated pneumatic nebulizer with corona discharge ionization. This ion source produced abundant [M + H]+ ions and a weak fragment ion due to loss of water. The protonated molecular ions at m/z 301 and 304 for methandrostenolone, 17-epimethandrostenolone and the internal standard were transmitted to the second quadrupole for collision-induced dissociation. Quantification was obtained by selected reaction monitoring of three daughter ions. Methandrostenolone and 17-epimethandrostenolone were separated by liquid chromatography, but gave identical mass spectra. The method detection limit by injection of a urine extract corresponding to 2.8 ml urine was 180 pg/ml at the 99% confidence level. The precision (relative standard deviation) was 3% at the 16 ng/ml level and the linear dynamic range was at least 3 orders of magnitude. Screening for unknown metabolites in urine after administration of methandrostenolone to horses and humans was accomplished by a parent ion scan of m/z 121, a fragment corresponding to the intact A-ring of the steroids.
尿样中加入[17-甲基-2H3]甲基雄烯醇酮作为内标，并用二氯甲烷和环己烷的混合物进行萃取。有机相浓缩后注入短的辛基硅胶柱（30 mm×4.6 mm内径），以分离甲基雄烯醇酮和17-表甲基雄烯醇酮。柱流出物连接到配备大气压离子源的Sciex TAGA 6000E三重四极杆质谱仪，该离子源用于对由带电晕放电电离的加热气动雾化器产生的离子进行采样。该离子源产生大量的[M + H]+离子以及因失水产生的弱碎片离子。甲基雄烯醇酮、17-表甲基雄烯醇酮和内标的质荷比为301和304的质子化分子离子被传输到第二个四极杆进行碰撞诱导解离。通过对三个子离子的选择反应监测进行定量。甲基雄烯醇酮和17-表甲基雄烯醇酮通过液相色谱分离，但给出相同的质谱图。在99%置信水平下，注入相当于2.8 ml尿液的尿提取物时，方法检测限为180 pg/ml。在16 ng/ml水平下，精密度（相对标准偏差）为3%，线性动态范围至少为3个数量级。对马和人施用甲基雄烯醇酮后尿液中未知代谢物的筛查通过对质荷比121的母离子扫描完成，121是对应于类固醇完整A环的一个碎片。
