Tobacco smoke xenobiotic compound appearance in mothers' milk after involuntary smoke exposures. I. Nicotine and cotinine.

In the development of the extraction procedure for the analysis of nicotine and cotinine from a single breast milk sample, nicotine and cotinine were detected in 3 of 10 nonsmoking mothers' milk samples. Interviews of these women revealed the presence of nonsmoking husbands and households but of tobacco smoke exposures during the working day. Clinically these levels may be considered inconsequential in regard to the threat to the mother and nursing infant but may be important in studies designed to monitor tobacco smoke xenobiotic compound appearance in breast milk.