The influence of relative humidity and gaseous ammonia on the sorption of nicotine onto carpet

The influence of relative humidity and gaseous ammonia on the sorption of nicotine onto carpet


English :
Sorption kinetics and equilibria of nicotine with polypropylene carpet were quantified at 0, 50, and 90% relative humidity (RH) and in the presence of 0-, 20-, and 40-ppm NH3. Nicotine was introduced into a 10-liter, carpet-covered, stainless steel chamber by flash evaporating of 50-?l pure liquid nicotine and then equilibrating of surface sorption for 30 min prior to outlet gas sampling. The chamber was controlled at an air exchange rate of 1.2 h-1. A XAD-4 resin tube was used to collect gas-phase nicotine and then desorbed and analyzed with a gas chromatography-mass spectrometer (GC/MS). Kinetic sorption parameters were determined by fitting a mass balance model to experimental results using a non linear regression. Results show that an equilibrium partition coefficient, ke, of nicotine tended to increase as the RH increased. In the presence of 20- and 40-ppm NH3, the values of ke decreased by 14-40% at 50 and 90% RH, but the effect of NH3 was not observed at 0% RH.