TIME-COURSE OF APPEARANCE OF COTININE IN HUMAN BEARD HAIR AFTER A SINGLE-DOSE OF NICOTINE

The time course of appearance of cotinine in saliva and in daily colle ctions of beard clippings was monitored by gas chromatography with mas s spectrometry in six volunteers who were nonsmokers following a singl e 30-min buccal administration of nicotine as a chewing gum. Salivary cotinine concentrations reached a plateau after 1.5 h and were nondete ctable (<0.3 ng/ml) 24 h after drug administration. Cotinine was detec ted in extracts of sodium hydroxide digests of beard hair in all subje cts on the third day after drug administration. Mean concentrations in beard peaked on day 5, and cotinine was not detected (<0.03 ng/mg) af ter day 7. The data indicate the main route for cotinine incorporation into beard is during hair growth. Transfer into beard from sweat is o f little importance. A role for transfer via sebum is equivocal.