Urine levels of nicotine and its metabolites in young population exposed to second-hand smoke in nightclubs: a pilot study.

The aim of this study was to investigate the extent of second-hand smoke exposure in younger population visiting nightclubs in Croatia by comparing the levels of nicotine and its main metabolites cotinine and trans-3'-hydroxycotinine (3HC) in urine samples taken from 22 participants before and after spending about three hours in a nightclub, stratified by smoking status (smokers and non-smokers). The samples were prepared by liquid-liquid extraction and analysed with gas chromatography-mass spectrometry. The presence of nicotine, cotinine, and 3HC was confirmed in all urine samples.