Determination of hydroxyl radicals with salicylic acid in aqueous nitrate and nitrite solutions

Article type: Research Article

Authors: YANG, Xi | ZHAN, Man-jun | KONG, Ling-ren | WANG, Lian-sheng

Affiliations: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China

Note: [] Corresponding author. E-mail: [email protected]

Abstract: The qualitative and quantitative analyses of reactive oxygen species are essential to determine their steady-state concentration and related reaction mechanisms in environmental aquatic systems. In this study, salicylic acid was employed as an innovative molecular probe of hydroxyl radical (OH) generated in aqueous nitrate and nitrite solutions through photochemical reactions. Kinetic studies showed that the steady-state concentrations of OH in aqueous NO_3^-(10 mmol/L, pH = 5) and NO_2^-(10 mmol/L, pH = 5) solutions under ultraviolet irradiation were at a same magnitude, 10^{-15} mol/L. Apparent quantum yields of OH at 313 nm were measured as 0.011 and 0.07 for NO_3^- and NO_2^- respectively, all comparable to the results of previous studies.

Keywords: photochemistry, hydroxyl radical, salicylic acid, nitrate, nitrite

Journal: Journal of Environmental Sciences, vol. 16, no. 4, pp. 687-689, 2004