Puff-by-puff and intrapuff analysis of cigarette smoke using infrared spectroscopy

Abstract

This paper reports new techniques for smoke analysis for single puffs and during a puff (intrapuff) with minimal adverse effects due to sampling. These new sampling techniques, combined with Fourier transform infrared (FTIR) spectroscopy, offer excellent approaches for measuring gaseous combustion products from burning cigarettes in real time. Near-infrared (NIR) laser scattering also is shown to provide a physical measurement of smoke based on aerosol visibility (AV) that can be related to chemical composition using FTIR in intrapuff smoke research. The absorbance of simple gases such as carbon dioxide (CO 2), carbon monoxide (CO), acetaldehyde (CH 3CHO), nitric oxide (NO), hydrogen cyanide (HCN), and carbonyl sulfide (COS) are determined on a puff-by-puff basis using FTIR spectroscopy. The aerosol portion of the smoke is separated from the gas phase by a Cambridge pad prior to the gas flowing into the gas cell for analysis. A decrease in HCN and CH 3CHO as a result of the effect of a Cambridge pad is lessened by decreasing the diameter of the pad and by replacing the pad between puffs. Each puff is trapped in a gas cell and analyzed between puffs. These results are compared with those measured using the conventional Cambridge filter pad and for whole smoke (no pad). In addition, the effect of the heat source and the lighting procedure on the lighting puff delivery of selected smoke components was studied. The absorbance of smoke constituents during a puff is determined using a flow-cell interface designed specifically for this measurement. Evolution profiles are reported for carbon dioxide, carbon monoxide, methane, and glycerine. Aerosol visibility is determined by NIR laser scattering using a separate flow cell located upstream. The evolution profile of the aerosol matches that of the glycerine profile demonstrating that an aerosol component can be monitored during the puff as well as purely gas phase components.