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CORESTA Meeting, Smoke Science/Product Technology, Jeju, 2007, SSPT 28

Analysis of vapor and particulate phase free radicals in mainstream cigarette smoke

TAKANAMI Y.; MORIYAMA T.
Japan Tobacco Inc., Tobacco Science Research Lab., Yokohama, Kanagawa, Japan.
Cigarette smoke contains various types of free radicals. Generally, the radicals are categorized into vapor phase radicals, particulate phase radicals and reactive oxygen species, which are analyzed by separate methodologies. In this report, the analytical conditions of the vapor and particulate phase radicals are investigated in detail to find analytical methods with robustness. A 20-port rotary smoking machine is used for smoke collection. For the vapor phase radical analysis, the cigarette smoke passes through a Cambridge filter and is bubbled with a PBN spin-trapping agent in benzene, and then the ESR spectrum of the solution is measured. For the particulate phase radical analysis, the tar collected on the Cambridge filter is extracted with benzene and the ESR spectrum of the solution is measured. The amount of the radicals is determined using calibration curves obtained from the ESR spectra of TEMPO. The method validation including the stability and linearity is examined. To improve the stability of the data, the aging effect of the radicals must be considered by the analytical conditions. To obtain results stable enough for evaluation of the vapor phase radicals, the timing of the analytical steps between smoking and ESR analysis is kept the same for each analysis. The particulate phase radicals are relatively stable and the aging effect is suppressed for a certain duration by cooling the Cambridge filter until the extraction. Good linearity is found between the amount of the vapor phase radicals and the number of cigarettes smoked. The precision of the amount of the particulate radicals is good; however, the linearity of the amount of the radicals and tar concentration is limited, especially for tar extracts with low concentrations. Further studies for obtaining the linearity of the analytical data will be needed, and the analytical results of some cigarette samples will be discussed.