Differences in the Chemical Composition of the Particulate Phase of Inhaled and Exhaled Cigarette Mainstream Smoke

Abstract

In this study, a comparison between the chemical composition of the particulate-phase of exhaled smoke and that of smoke generated with a smoking machine has been performed. For this purpose, eight human subjects smoked a common Lights (10.6 mg ‘tar’/cig) commercial cigarette and the exhaled particulate-phase smoke from three cigarettes was collected on Cambridge pads for each smoker. The smoke collection from the human subjects was vacuum assisted. The cigarette butts from the smokers were collected and analyzed for nicotine. The machine smoking was performed with a Borgwaldt RM20 CSR smoking machine working under conditions recommended by the U.S. Federal Trade Commission (FTC). The nicotine levels for the cigarette butts from the smokers were used to normalize the level of exhaled smoke condensate to that of the FTC smoking conditions. The smoke condensates from exhaled smoke as well as that from the machine smoking were analyzed by a gas chromatographic technique with mass spectral peak identification. The retention efficiency for 160 compounds was calculated from the ratio of the compound peak areas in the exhaled smoke (normalized by the corresponding butt nicotine level) vs. the areas of the corresponding peaks from the chromatogram of the smoke generated by the smoking machine. In the calculation of the results, it was assumed that the composition of mainstream smoke remains practically constant at different smoking regimes. All compounds found in the machine-generated smoke were also present in the exhaled smoke, but at different levels. About one third of the compounds were retained more than 66% by the smoker. Another third of the compounds were retained between 33% and 66%, and the rest of the compounds were retained very little from the mainstream particulate-phase of the cigarette smoke. The compounds retained more than 66% were in general compounds with lower molecular weight and with higher water solubility, which eluted first from a 5% phenyl dimethyl-polysiloxane (DB-5MS) chromatographic column. The compounds retained less than 33% from smoke were those with higher molecular weights and boiling points, which had longer elution times from the chromatographic column. These compounds consisted mainly of long-chain hydrocarbons (saturated or squalene type) and phytosterol-type compounds. The compounds retained between 33% and 66% had intermediate chromatographic retention times. No attempt was made to evaluate or identify new compounds formed in the exhaled smoke. The results were obtained from a limited number of subjects, but among these the retentions for individual compounds did not show large differences, indicating that the retention process is not very different for the subjects evaluated. An attempt was made to verify whether or not the retention of compounds by the smoker is analogous to a distribution process. Only weak correlations were obtained between the human retention and octanol/water partition coefficients or between the human retention and the chromatographic retention times of individual compounds.

Smokers of Menthol and Nonmenthol Cigarettes Exhibit Similar Levels of Biomarkers of Smoke Exposure

“…The recent development of improved methods to measure the lung deposition and retention of individual cigarette smoke constituents in human smokers (41,42) suggests that better estimates of both local and systemic exposures to menthol or to other smoke constituents of greater toxicologic interest may soon be attainable.…”

Particle Size Distribution of Mainstream and Exhaled Cigarette Smoke and Predictive Deposition in Human Respiratory Tract

“…The mainstream smoke which goes as a puff in smoker's mouth through filter and side stream smoke which is emitted in air from the burning end of cigarette (not through filter). Deposition of mainstream cigarette smoke (MCS) in the respiratory tract is a key mechanism for exposure of smokers to smoke constituents and in understanding smoking-related disease (Feng et al, 2007;Moldoveanu and St. Charles, 2007). The particles in Environmental Tobacco Smoke (ETS) are derived from particles in fresh mainstream and side stream smoke.…”

A Robust Method for Estimating Human Smoked Cigarette Yields from Filter Analysis Data

“…Nicotine yields determined by the part-filter method have also been shown to correlate significantly with the more traditional measurements of nicotine uptake such as 24-h urinary nicotine plus metabolites and saliva cotinine (11). The part-filter method has also been used to estimate HS cigarette yields in market surveys (12), perform postmarket surveillance of new product launches (13) and has also been used to estimate the yield of smoke constituents other than 'tar' and nicotine as an aid in determining their retention efficiency in humans (14,15). The objective of this paper is to describe the part-filter methodology in detail as it is currently being practiced at British American Tobacco (BAT), along with experiences discovered while using this methodology, storage effects, quality control measures, repeatability and reproducibility.…”