Tomita M, Okuyama T, Sato S, Ishizu H
Department of Legal Medicine, Kawasaki Medical School, Kurashiki, Japan.
J Chromatogr. 1993 Nov 24;621(2):249-55. doi: 10.1016/0378-4347(93)80102-a.
We applied micellar electrokinetic capillary chromatography to simultaneous separation and determination of nitrazepam and its major metabolites, 7-aminonitrazepam and 7-acetamidonitrazepam, in spiked urine. Prior to electrophoresis, the three compounds were successfully extracted from the spiked urine with commercial disposable solid-phase cartridges. The optimum running buffer for the separation was prepared by combining 85 parts of 60 mM sodium dodecyl sulphate-6 mM phosphate-borate, adjusted to pH 8.5, with 15 parts of methanol. The separation order, completed within 25 min, was 7-aminonitrazepam > 7-acetamidonitrazepam > nitrazepam, at an applied potential of 20 kV. We obtained reproducible electropherograms in successive repetitions, and few other peaks or interferences appeared in the electropherogram. The detection limits of the three compounds were 50-100 pg (0.1-0.2 microgram/ml of analyte in spiked urine), and the recoveries were 78.9-100.8% for 1 microgram/ml and 84.1-100.3% for 5 micrograms/ml. The application of this method to forensic or clinical samples is demonstrated.
我们应用胶束电动毛细管色谱法同时分离并测定加标尿液中的硝西泮及其主要代谢物7-氨基硝西泮和7-乙酰氨基硝西泮。在进行电泳之前，使用市售一次性固相柱成功地从加标尿液中提取出这三种化合物。分离的最佳运行缓冲液是由85份pH值调至8.5的60 mM十二烷基硫酸钠 - 6 mM磷酸盐 - 硼酸盐与15份甲醇混合而成。在20 kV的施加电压下，25分钟内完成的分离顺序为7-氨基硝西泮> 7-乙酰氨基硝西泮>硝西泮。我们在连续重复测定中获得了可重现的电泳图，并且电泳图中几乎没有其他峰或干扰出现。这三种化合物的检测限为50 - 100 pg（加标尿液中分析物浓度为0.1 - 0.2微克/毫升），对于1微克/毫升的回收率为78.9 - 100.8%，对于5微克/毫升的回收率为84.1 - 100.3%。本文展示了该方法在法医或临床样本中的应用。
