Nicotine monitoring in sweat with a sweat patch

In recent years, remarkable advances in sensitive analytical techniques have enabled the analysis of drugs in unconventional samples, such as sweat. In a study conducted with cigarettes smokers and nonsmokers, PharmChek sweat patches were applied to 29 subjects for 72 h. Nicotine was extracted in 5 ml methanol in the presence of 200 ng nicotine-d(4), used as internal standard. After 20 min agitation, the methanolic solution was evaporated to dryness in the presence of 10 mu l octanol to ensure nonvolatility of nicotine. Nicotine was determined using gas chromatography coupled to mass spectrometry after separation on a 30-m capillary HP5 MS column. The assay was linear in the range 50-2500 ng/patch, with an extraction recovery of 76+/-5%. Limit of detection was 10 ng/patch. Nicotine concentrations in sweat were not detected for the nonexposed nonsmokers (n=8), 87 to 266 ng/patch for the passive smokers (n=6) and 150 to 2498 ng/patch for the smokers (n=15). This study demonstrated a useful application of the sweat patch for monitoring tobacco exposure. (C) 1998 Elsevier Science B.V.