ENANTIOSELECTIVE DETERMINATION OF ZOPICLONE AND ITS METABOLITES IN URINE BY CAPILLARY ELECTROPHORESIS

A method has been developed for the stereoselective determination of z opiclone and its main metabolites in urine. After the addition of the internal standard zolpidem the urine samples were extracted at pH 8 wi th chloroform-isopropanol (9:1). Analyses were carried out using capil lary electrophoresis (CE) with P-cyclodextrin as the chiral selector. The analytes were detected using UV lases-induced fluorescence detecti on with a He-Cd laser operated at 325 nm. Urine samples of two volunte ers after oral administration of 7.5 mg zopiclone were investigated. T he S-(+)-enantiomers of zopiclone and its metabolites were always excr eted in higher amounts than the R-(-)-enantiomers. With the same metho d the zopiclone enantiomers were quantified in saliva. Compared to hig h-performance liquid chromatography, the CE method is very fast and si mple.