Nicotine has been used as a selective marker to evaluate environmental tobacco smoke (ETS). In this study, a simple and precise nicotine measurement method using a solid phase cartridge (Sep-Pak((R)) Plus PS-2) followed by GC-MS analysis was evaluated. Prior to use, the solid phase cartridge was coated with potassium hydroxide (KOH), and indoor air was then passed through it. After the air sampling, nicotine was eluted from the cartridge with 10 mu g/ml triethylamine/dichloromethane, and the eluent was analyzed by GC-MS. The nicotine recovery from the spiked cartridge was more than 80% for an air sampling time of 12 hr, and the method detection limit (MDL) for the air sampling with an air volume of 721 was 0.35 mu g/m(3). When the cartridge was used for indoor air measurement, the nicotine concentrations in the smoking room ranged from 12.9 mu g/m(3) to 86.6 mu g/m(3), which were proportional to the number of smoked cigarettes.