DISPOSITION OF NICOTINE AND 8 METABOLITES IN SMOKERS AND NONSMOKERS - IDENTIFICATION IN SMOKERS OF 2 METABOLITES THAT ARE LONGER LIVED THAN COTININE

The disposition of a single intravenous dose of C-14-nicotine was investigated in six cigarette smokers and six nonsmokers. Plasma and urinary elimination of both nicotine and cotinine was faster in smokers than in nonsmokers. In the urine of both smokers and nonsmokers, we identified nicotine and eight metabolites, including two new metabolites: metabolite A (3-hydroxycotinine glucuronide) and metabolite G (demethylcotinine-delta-2',3'-enamine). Metabolites A and G were of particular interest because, in smokers, they both persisted longer than cotinine. This property renders them more sensitive than cotinine as potential indicators of passive exposure to cigarette smoke.