ON THE DISTRIBUTION OF NICOTINE BETWEEN THE GAS AND PARTICLE PHASE AND ITS MEASUREMENT

A method is described which allows the separate sampling and analysis of gaseous and particulate nicotine with a denuder-filter combination. Recovery rates of 101.6 +/- 3.6% are found for a denuder coated with benzenesulfonic acid. Particulate nicotine can be sampled with glass-f iber filters which are also impregnated with benzenesulfonic acid. The extracts of the denuders and filters are quantified by gas chromatogr aphy (GC/FID) after reextraction from 0.1 N NaOH into CH2Cl2. A determ ination limit of 5 ng (abs.) is reached by use of n-hexadecane as an i nternal standard. This sampling system is interesting especially for t he determination of semi-volatile compounds, such as nicotine, the dis tribution of which affects its efficiency in smoking. The different di stribution of nicotine between the gas and particle phase in the prese nce of various additives was examined in model test systems. These may give evidence on the behavior of nicotine in cigarette smoke, whose e ffects may influence its distribution between main- and sidestream smo ke. Gas-particle mixtures of nicotine are generated in different ways. The characterization of these mixtures is accomplished with physical methods for the measurement of particle concentration and size, and ar e verified by diffusive sampling and gas chromatographic analysis. It was found that for different test systems, nicotine-containing aerosol is only formed when the carrier particle is of an acidic nature and t he nicotine is attached as a salt. In this way, the dispersion of aque ous potassium hydrogensulfate, citric, tartaric, or other organic acid solutions as submicron aerosols containing nicotine leads to a nicoti ne-containing aerosol. Also, phenol-containing aerosols can be formed under well-defined conditions. These aerosols as well as the distribut ion of nicotine are models of semi-volatile compounds with a distinct pH dependence for applications other than cigarette smoke as well. (C) 1997 American Association for Aerosol Research.