Determination of hydroxyl radicals in advanced oxidation processes with dimethyl sulfoxide trapping and liquid chromatography Original Research Article

In this paper, a simple and sensitive method for the determination of hydroxyl radicals generated in advanced oxidation processes is described. The proposed method employed the reaction between hydroxyl radicals and dimethyl sulfoxide (DMSO) to generate quantitatively formaldehyde, which then reacted with 2,4-dinitrophenylhydrazine (DNPH) to form the corresponding hydrazone (HCHO–DNPH) and analyzed by liquid chromatography-UV. Factors affecting the derivatization reaction of HCHO and trapping reaction of hydroxyl radicals, as well as the applicability of the method, were investigated. The detection limit for hydroxyl radicals was 0.54 μmol L−1. The method had been used to determine the yield of hydroxyl radicals in various advanced oxidation processes (AOPs) to compare their oxidation ability.