Energy security and climate change concerns have led to the promotion of biomass-derived ethanol, an oxygenated volatile organic compound (OVOC), as a substitute for fossil fuels. Although ethanol is ubiquitous in the troposphere, our knowledge of its current atmospheric budget and distribution is limited. Here, for the first time we use a global chemical transport model in conjunction with atm...

Chlorpromazine and several other related phenothiazines are known to cause both phototoxic and photoallergic reactions in the skin and eyes of patients receiving these drugs. While the detailed mechanisms of photosensitization are not known, it is obvious that the first step must be the absorption of light by the drug, its metabolites, or photoproducts, or possibly an induced endogenous chemica...

BACKGROUND 2-t-Butyl-4-methoxyphenol (BHA) has considerable toxicity and undesirable potential tumor-promoting activities. To clarify the free radical mechanism of BHA-induced toxicity, the comparative radical-scavenging activity of BHA and its dimer (bis-BHA, 3,3'-ditert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diol) with or without 2-mercapto-1-methylimidazole (MMI) was studied using the induc...

The measurements of the overall bicyclic peroxy radical + NO rate constant for the 1,3,5-trimethylbenzene (1,3,5-TMB) system and of the nitrate product yields for the benzene, toluene, p-xylene, and 1,3,5-TMB systems were performed via the turbulent flow chemical ionization mass spectrometry technique. While the overall rate constant was found to be consistent with the value used in the most de...

Nitric oxide (NO) is relatively harmless, but along with superoxide radical becomes precursor of many toxic species, such as peroxy and hydroxyl radicals, hydrogen peroxide, and peroxynitrite. In the present study, we determined plasma NO as a function of human age and correlated NO levels with total antioxidant capacity of the plasma. Results showed significant increase in NO level as a functi...

The OH initiated oxidation of 1,3,5-trimethylbenzene (1,3,5-TMB) under NOx-free conditions has been investigated by using a home-made vacuum ultraviolet (VUV) photoionization aerosol mass spectrometer complemented high-level theoretical computations. chemical composition the nascent particles from reaction is measured on-line and high O2-bridged bicyclic compounds in particle phase are directly...

Methyl peroxy, a key radical in tropospheric chemistry, was recently shown to react with the hydroxyl radical at an unexpectedly high rate. Here, the molecular reaction mechanisms are elucidated using high-level quantum chemical methodologies and statistical rate theory. Formation of activated methylhydrotrioxide, followed by dissociation into methoxy and hydroperoxy radicals, is found to be th...

Recent work has shown that the atmospheric oxidation of isoprene (2-methyl-1,3-butadiene, C5H8) leads to the formation of secondary organic aerosol (SOA). In this study, the mechanism of SOA formation by isoprene photooxidation is comprehensively investigated, by measurements of SOA yields over a range of experimental conditions, namely isoprene and NOx concentrations. Hydrogen peroxide is used...