Determination of nicotine and its major metabolite cotinine in plasma or serum by gas chromatography-mass spectrometry using ion-trap detection.

摘要

A specific method has been developed for the quantitative determination of nicotine and its major metabolite cotinine in plasma or serum of active and passive smokers. Deuterium-labelled nicotine and cotinine were used as internal standards. The amounts of nicotine and cotinine present in a sample of plasma or serum were extracted with a simple extraction procedure (liquid-liquid or solid-phase extraction). The extracts were analysed by gas chromatography coupled with mass spectrometry using ion-trap detection. The analysis was done in positive chemical ionisation with methanol as the liquid reagent. The method has been demonstrated to be linear up to 1000 microg/l. Limits of quantification for nicotine and cotinine are 10 and 5 microg/l, respectively with liquid-liquid extraction, and 1 microg/l for each of the compounds with solid-phase extraction. The present method has been applied to several real cases.