DETERMINATION OF NICOTINE AND 4 METABOLITES IN THE SERUM OF SMOKERS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ULTRAVIOLET DETECTION

A simple and reliable reversed-phase high-performance liquid chromatog raphic method with ultraviolet detection is described for the quantita tion of nicotine and its metabolites cotinine, trans-3'-hydroxycotinin e, norcotinine and cotinine N-oxide in human serum. The analytes and t he internal standard, N-ethylnorcotinine, were extracted by solid-phas e extraction before chromatography. Two different columns and mobile p hases with gradient systems were used. The detection limit of the assa y was 10 ng/ml for nicotine, 3 ng/ml for cotinine N-oxide and 5 ng/ml for cotinine, trans-3'-hydroxycotinine and norcotinine. The concentrat ions of nicotine and its metabolites in the serum of 12 cigarette smok ers are reported.