Rapid Measurement of Aqueous Hydroxyl Radical Concentrations in Steady-State HOFlux Systems

摘要

In recent years the hydroxyl radical (HO.) has become the focus of a significantbody of research concerning the chemical oxidation of anthropogenic organic compounds in the environment. The spin-trap compound alpha-(4-pyridyl-1-oxide)-N-tert-butyl-nitrone (4-POBN) is utilized for the detection and quantitation of the hydroxyl radical (HO) in aqueous solution. Capillary electrophoresis enables rapid analysis of the probe compound. The thermally unstable HO radical adduct of 4-POBN can be unequivocally identified by gas chromatography / mass spectrometry analysis of it's pentafluorobenzyl ether. The minimum steady-state flux of HO. is determined in several advanced oxidation systems including photo-Fenton, ozone, and titanium dioxide based radical generators.