Detection of Hydroxyl Radicals with Salicylic Acid

Abstract

Salicylate was hydroxylated by hydroxyl radicals formed in the system composed of hypoxanthine-xanthine oxidase and a ferrous iron salt. The hydroxylated products of salicylate, namely, 2, 3-dihydroxybenzoate, 2, 5-dihydroxybenzoate and 2, 6-dihydroxybenzoate, were identified by thin-layer chromatography and high performance liquid chromatography (HPLC). The relative standard deviation was 7.98% (n=5) and the detection limit for 2, 5-dihydroxybenzoate formed from salicylate was 0.555ng/ml (S/N=3). This method was employed for the detection of hydroxyl radicals generated in polymorphonuclear leukocytes during stimulation by opsonized zymosan. The generation of hydroxyl radicals increased with increasing incubation period up to 40min.