Electron paramagnetic resonance investigation of the free radicals in the gas and particulate phases of cigarette smoke using spin-trapping techniques

Abstract

Free radicals in cigarette smoke have been studied using spin trapping EPR techniques. 2R4F reference cigarettes were smoked using 35 ml puff volumes of 2 seconds duration, once every 60 seconds. The particulate phase of the smoke was separated from the gas phase by passing the smoke through a Cambridge filter pad. For both phases, free radicals were measured and identified. A range of spin-traps was employed: PBN, DMPO, DEPMPO, and DPPH-PBN. In the gas-phase, short-lived carbon-and oxygen-centered radicals were identified; the ratios between them changed during the smoking runs. For the first puffs, C-centered radicals predominated while for the later puffs, O-centered radicals were mainly observed. The particulate phase and the 'tar' were studied as well.

Combustion By-Products and Their Health Effects—Combustion Engineering and Global Health in the 21st Century

“…The flow EPR method allowed for the identification of free radicals that have a very short lifetime (<1 minute), whereas the addition of a spin trap increased the lifetime of the free radicals allowing for more detailed chemical composition of free radical species. 22 The spin trapping technique forms a spectrum that serves as a “fingerprint” or a spectral “snapshot” of the radical under investigation. With these techniques, she and her colleagues have demonstrated that at room temperature and in presence of ozone, internal double bonds in acoustically levitated terpene droplets are unstable.…”