Abstract
The equilibrium headspace concentration of nicotine in nitrogen gas was measured by gas chromatography for binary mixtures of nicotine with glycerol and with 1,2-propanediol at temperatures near 298.15 K. The storage temperature ranged from 296.25 to 298.25 K. The nicotine mole fraction ranged from 0.0015 ± 0.00010 to 0.998 ± 0.0016 for the glycerol mixtures and 0.00506 ± 0.000019 to 0.999 ± 0.0038 for the 1,2-propanediol mixtures (k = 2 expanded uncertainty). The headspace concentration was converted to nicotine partial pressure at 298.15 K using the ideal gas law, followed by the Clausius-Clapeyron equation. Both solvent systems had a positive deviation of nicotine partial pressure from ideal behavior, but the deviation of the glycerol mixtures was much greater than that of the 1,2-propanediol mixtures. For mole fractions of about 0.02 or less, the glycerol mixtures had nicotine activity coefficients of 11, while that for the 1,2-propanediol mixtures was 1.5. The Henry's law volatility constant and infinite dilution activity coefficient ± expanded uncertainty for nicotine from glycerol mixtures (51.4 ± 1.8 Pa and 12.4 ± 1.5, respectively) were approximately an order of magnitude greater than those from 1,2-propanediol mixtures (5.26 ± 0.52 Pa and 1.42 ± 0.14, respectively).