Radicals from the Oxidative Pyrolysis of Tobacco

Abstract

The fractional, oxidative pyrolysis of Bright tobacco was performed in an oxygen/nitrogen atmosphere containing from 0 to 20.4% of O2 over the temperature range of 200–510 °C in a specially constructed, high-temperature flow reactor system. The effect of the temperature and the concentration of oxygen in the reaction atmosphere on the generation of free radicals from Bright tobacco and two major components of Bright tobacco (polyphenols and cell wall biopolymers) were studied. Electron paramagnetic resonance (EPR) spectroscopy was used to analyze for free radicals in the initially produced total particular matter (TPM) and in the gas phase. Two types of radicals were observed in the initially produced TPM: type I radicals characterized by a five-line EPR spectrum with an apparent g-value of ∼2.0064 that was tentatively assigned to a tyrosyl radical formed at lower temperatures from the cell wall biopolymer fraction of tobacco, and type II radicals characterized by a single-line EPR spectrum with g-factor ...