Trans-3?-hydroxycotinine as a main metabolite in urine of smokers

Abstract
Nine mal smokers smoked three types of cigarettes that differed in mainstream nicotine. The experiment was carried out in three runs, each consisting of 7 d when smoking was allowed and 5 d when it was not allowed. Urine fractions were collected throughout the whole period of the experiments. As assumed, nicotine and four of its known metabolites, i.e., cotinine, nicotine-N′-oxide, nornicotine, and N-methyl-nicotinum ions were found in the urine. In addition, trans-3′- hydroxycotinine was determined. The amount of this metabolite was well in excess of those of nicotine and cotinine in the urine. The serum concentration trans-3′-hydroxycotinine was found to be second to serum cotinine.