Polycyclic aromatic hydrocarbons (PAHs) are a class of environmental pollutants created primarily from incomplete combustion of various organic materials including tobacco. Cigarette smoke is a complex mixture of various classes of compounds, including numerous PAHs, in both the mainstream and the sidestream smoke fractions. We measured the levels of 14 PAHs in mainstream smoke from unfiltered custom cigarettes made from individual tobacco types and 30 brands of domestic blended cigarettes using standardized smoking conditions, extraction from the Cambridge filter pads, and gas chromatography/mass spectrometry. Differences in smoke PAHs from cigarettes with selected tobacco blends were identified and illustrate how blend composition contributes to the overall mainstream smoke PAH profile. The PAH levels varied among the different commercial cigarette brands, with the amount of total mainstream smoke PAHs ranging from 1 to 1.6 microg per cigarette. Under machine smoking conditions, the mainstream smoke from domestic cigarettes had individual PAHs ranging from benzo[k]fluoranthene at levels below 10 ng/cigarette to naphthalene at levels of around 500 ng/cigarette. Low delivery cigarettes smoked with blocked filter vent holes dramatically increased the mainstream smoke PAH deliveries with respect to their unblocked counterparts. Inhalation of PAHs and other harmful chemicals from cigarette smoke are unique as they represent a routine voluntary exposure to common environmental pollutants.

Characterizing nicotine delivery from tobacco products is important in the understanding of their addictive potential. Most previous studies report total nicotine and have not differentiated between nicotine in its protonated or free-base form. Rather than simply determining total nicotine, the method described in this paper determines the amount of free-base nicotine associated with trapped mainstream smoke particulate matter generated using a standardized smoking machine protocol. This method quantitatively determines volatile free-base nicotine associated with the particulate phase portion of mainstream cigarette smoke using solid-phase microextraction combined with gas chromatography-mass spectrometry. The headspace above total particulate matter from mainstream cigarette smoke trapped on a Cambridge filter pad (CFP) was analyzed for free-base nicotine in 26 cigarette brands. The selected cigarette brands were chosen to cover a wide range of tar and nicotine deliveries as measured under Federal Trade Commission machine smoking conditions. In the CFP's headspace the free-base nicotine levels ranged from 0.01 to 0.08 mg/cigarette. The measured ranges of free-base nicotine were remarkably similar over the different tar and nicotine delivery categories of full-flavored, light, and ultralight cigarette brands.