SIMULTANEOUS DETERMINATION OF ZOLPIDEM AND ZOPICLONE IN HUMAN PLASMA BY GAS CHROMATOGRAPHY-NITROGEN-PHOSPHORUS DETECTION

A simple, specific and selective method for the simultaneous determina tion of zolpidem and zopiclone in human plasma is described. After a l iquid-liquid extraction, the extract is injected into a capillary gas chromatograph with an OV-1 fused-silica column coupled to a nitrogen-p hosphorus detector. The detection limits are 1 and 2 ng/ml for zolpide m and zopiclone, respectively. The method described is reproducible an d linear over a range of concentrations, rendering it suitable for use for pharmacokinetic studies or toxicological evaluations. Absolute id entification of the chromatographed compounds is accomplished by gas c hromatography-mass spectrometry in both electron-impact and positive-i on chemical ionisation modes.