Rapid and sensitive high-performance liquid chromatographic determination of nicotine and cotinine in nonsmoker human and rat urines

A simple reversed-phase high-performance liquid chromatographic method with paired-ion and UV detection has been developed for the rapid quantification of urinary nicotine and cotinine. A one-step solid-liquid extraction on Exvelut(R) was used. Separation from endogenous substances was achieved with a decreasing flow-rate. With 20 ml of urine for extraction, the limit of quantification was 0.5 ng/ml for cotinine and 5 ng/ml for nicotine; linearity was obtained from 50 to 5000 ng/ml. The intra-and inter-day coefficients of variation were less than 9% for cotinine and 30% for nicotine. Average recoveries for cotinine were 92-100% and 47-86% for nicotine. The present method was applied to the urine analysis of smokers, nonsmoker children, and experimental animals. (C) 1998 Elsevier Science B.V.