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

This paper reports new techniques for smoke analysis for single puffs and d uring a puff (intrapuff) with minimal adverse effects due to sampling. Thes e new sampling techniques, combined with Fourier transform infrared (FTIR) spectroscopy, offer excellent approaches for measuring gaseous combustion p roducts from burning cigarettes in real time. Near-infrared (NIR) laser sca ttering also is shown to provide a physical measurement of smoke based on a erosol visibility (AV) that can be related to chemical composition using FT IR in intrapuff smoke research. The absorbance of simple gases such as carbon dioxide (CO2), carbon monoxid e (CO), acetaldehyde (CH3CHO), nitric oxide (NO), hydrogen cyanide (HCN), a nd 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 p hase by a Cambridge pad prior to the gas flowing into the gas cell for anal ysis. A decrease in HCN and CH3CHO 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 convention al Cambridge filter pad and for whole smoke (no pad). In addition, the effe ct of the heat source and the lighting procedure on the lighting puff deliv ery of selected smoke components was studied. The absorbance of smoke constituents during a puff is determined using a fl ow-cell interface designed specifically for this measurement. Evolution pro files are reported for carbon dioxide, carbon monoxide, methane, and glycer ine. Aerosol visibility is determined by NIR laser scattering using a separ ate flow cell located upstream. The evolution profile of the aerosol matche s that of the glycerine profile demonstrating that an aerosol component can be monitored during the puff as well as purely gas phase components. (C) 2 001 Elsevier Science B.V. All rights reserved.