Greenblatt D J
Clin Chem. 1978 Oct;24(10):1838-41.
Electron-capture gas-liquid chromatography was used for simultaneous quantitation of plasma diazepam (I) and its major metabolite, desmethyldiazepam(II). Because concentrations of I can greatly exceed those of II after single doses of I, two benzodiazepine-analog internal standards were added to all samples, thereby allowing reliable quantitation of high concentrations of I and low concentrations of II. After extraction at neutral pH with benzene (containing isoamyl alcohol), the organic extract is evaporated and the residue is reconstituted in a small volume of solvent and chromatographed on a 3% OV-17 column. The sensitivity limits are 2 to 3 ng of I or II per milliliter of original sample, with a CV for identical samples of less than 5%. The applicability of the method to single-dose pharmacokinetic studies of I in humans is illustrated.
电子捕获气液色谱法用于同时定量血浆中的地西泮（I）及其主要代谢物去甲基地西泮（II）。由于单次给予地西泮后，I的浓度会大大超过II的浓度，因此在所有样品中添加了两种苯二氮䓬类似物内标，从而能够可靠地定量高浓度的I和低浓度的II。在中性pH下用苯（含异戊醇）萃取后，将有机萃取物蒸发，残留物用少量溶剂复溶，并在3% OV - 17柱上进行色谱分析。灵敏度极限为每毫升原始样品中I或II 2至3纳克，相同样品的变异系数小于5%。文中举例说明了该方法在人体I单剂量药代动力学研究中的适用性。
