Determination of OH Rate Constants for Six Volatile Organics in Air Using the UCR (University of California-Riverside) Protocol

摘要

An important mechanism of chemical transformation of organic pollutants in the atmosphere is through oxidation by OH radicals. A relatively simple laboratory procedure for determining the OH rate constants in air was developed. To determine the rate, a teflon bag is filled with 10-15 ppm of methyl nitrite, 5 ppm of nitric oxide, 2 ppm of test compound, and 2 ppm of an organic which has an accurately known OH rate constant. The mixture is irradiated with blacklamps and the concentrations of the reference and test organic are measured over a 45-minute period. Results are detailed in the report.