[Determination of zopiclone in serum by reversed-phase high performance liquid chromatography]

A reversed-phase high performance liquid chromatographic method (external standard method) was developed for the determination of zopiclone in serum. After the selective extraction with n-butyl chloride, this compound was chromatographed on a LiChroCART 125-4 column packed with LiChrospher 60 RP select B(5 microns) using acetonitrile-monopotassium phosphate (20:80, V/V) as mobile phase. The eluting compound was measured by an ultraviolet detector at 254 nm. Spiked with zopiclone of 400 micrograms/L, 1,600 micrograms/L and 6,400 micrograms/L in serum, the recoveries of zopiclone were (73.4 +/- 3.2)%, (82.2 +/- 4.1)% and (90.3 +/- 4.5)% respectively. The detection limit of the method was 15 micrograms/L. The method is simple and rapid for the determination of zopiclone in forensic toxicology.