Degradation of 2,4-dihydroxibenzoic acid by vacuum UV process in aqueous solution: Kinetic, identification of intermediates and reaction pathway

► Degradation of 2,4-dihydroxybenzoic acid (DHBA) by vacuum UV photolysis of water. ► V-UV Xe-excimer lamps produced essentially hydroxyl radicals (HO°). ► Identification of all intermediates formed allowed us to propose a reaction pathway. ► This reaction pathway showed that DHBA reacts differently with HO° and h+. ► DHBA would be used as a probe to determine which of these entities were involved.