We used an improved method for trapping carbon-centered radicals (.R) from the gas-phase to compare radical suites trapped from various tobacco smoke and model smoke systems. Using a nitroxide trap, 3-amino-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (3AP), on solid support, we trapped radicals directly from the gas phase, washed them off the support, and analyzed them with HPLC. Separation of the trapped radicals showed that each tobacco type produced a unique radical suite of 4-10 distinct peaks. Gas mixtures used to model tobacco smoke consisted of nitric oxide, air, isoprene, and methanol. The model systems produced radical suites of four major and several minor peaks, two of which matched peaks in tobacco smoke chromatograms. Quantities of radicals trapped from tobacco smoke were: 54 +/- 2 nmol .R per Marlboro cigarette, 66 +/- 9 nmol .R per Djarum clove cigarette, and 185 +/- 9 nmol .R per Swisher Sweet cigar. In these experiments oxygen competes with the nitroxide trap for gas-phase radicals. A kinetic analysis of the O2 competition shows that actual radical concentrations in the smoke were approximately 100-fold higher than measured.

Carbon-centered radicals were trapped from gas-phase cigarette smoke and diesel engine exhaust by reaction with a nitroxide, 3-amino-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (3AP). The resulting mixture of stable, diamagnetic adducts was derivatized with naphthalenedicarboxaldehyde (NDA) to produce highly fluorescent products. Derivatives were separated by high-performance liquid chromatography (HPLC), which revealed distinctly different suites of radicals present in the two systems. Integration of HPLC peaks gave approximately 22 ± 7 nmol of radicals per cigarette and 3 ± 1 nmol of radicals per liter of diesel engine exhaust. An estimated 8-10 different carbon-centered radical species are present in each system.

We used an improved method for trapping carbon-centered radicals (•R) from the gas-phase to compare radical suites trapped from various tobacco smoke and model smoke systems. Using a nitroxide trap, 3-amino-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (3AP), on solid support, we trapped radicals directly from the gas phase, washed them off the support, and analyzed them with HPLC. Separation of the trapped radicals showed that each tobacco type produced a unique radical suite of 4-10 distinct peaks. Gas mixtures used to model tobacco smoke consisted of nitric oxide, air, isoprene, and methanol. The model systems produced radical suites of four major and several minor peaks, two of which matched peaks in tobacco smoke chromatograms. Quantities of radicals trapped from tobacco smoke were: 54 ± 2 nmol •R per Marlboro cigarette, 66 ± 9 nmol •R per Djarum clove cigarette, and 185 ± 9 nmol •R per Swisher Sweet cigar. In these experiments oxygen competes with the nitroxide trap for gas-phase radicals. A kinetic analysis of the O 2 competition shows that actual radical concentrations in the smoke were approximately 100-fold higher than measured.

No abstract