Monitoring of the smoking process by multicommutation Fourier transform infrared spectroscopy.

Nicotine was selected as the target molecule for monitoring of the smoking process by multicommutation Fourier Transform Infrared spectroscopy (FTIR). The method involved the use of CHCl3 for on-line extraction of nicotine from tobacco, cigarette filters and tobacco ash from NH4OH alkalinized samples, and absorbance measurement of the characteristic band at 1316 cm(-1) in the stopped-flow mode, by obtaining the peak area in the range between 1334 and 1300 cm(-1). Under the best operational conditions, the procedure developed provided a detection limit of 0.05 mg mL(-1) nicotine, corresponding to 0.5 mg g(-1) in the solid sample, a relative standard deviation less than 2.5%, and a sampling frequency of 12 determinations h(-1). It can be concluded that nicotine migrates in the smoke mainstream towards the filter during the smoking process. The smoking of cigarettes and cigars is different. Nicotine is retained weakly by both tobacco and filter in the case of cigarettes, and strongly by the unburned tobacco in cigars. The incomplete smoking of cigars and cigarettes reduces nicotine intake and thus reduces the additive effect.