Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 6 9 2006 10.5194/acp-6-2439-2006 http://www.atmos-chem-phys.net/6/2439/2006/ http://www.atmos-chem-phys.net/6/2439/2006/acp-6-2439-2006.html http://www.atmos-chem-phys.net/6/2439/2006/acp-6-2439-2006.pdf 2439 2451 2006-06-29 A chemical probe technique for the determination of reactive halogen species in aqueous solution: Part 2 – chloride solutions and mixed bromide/chloride solutions C. Anastasio canastasio@ucdavis.edu B. M. Matthew Atmospheric Science Program, Department of Land, Air & Water Resources, University of California, Davis, USA now at: Hach Company, Loveland, Colorado, USA Although reactive halogen species (X*=X•, •X₂^-, X₂ and HOX, where X=Br, Cl, or I) are important environmental oxidants, relatively little is known about their kinetics in condensed phases such as seawater and sea-salt particles. Here we describe a new technique to determine reactive chlorine and bromine species in aqueous solutions by using allyl alcohol (CH₂=CHCH₂OH) as a chemical probe. This probe is combined with competition kinetics in order to determine steady state concentrations of X*(aq). In some cases the technique also can be used to determine the rates of formation and lifetimes of X* in aqueous solution. In a companion paper we reported the results of our method development for aqueous solutions containing only bromide (Br^-). In this paper, we discuss method development for solutions containing chloride (Cl^-) alone, and for solutions containing both bromide and chloride. Anastasio, C., Faust, B. C., and Allen, J. M.: Aqueous phase photochemical formation of hydrogen peroxide in authentic cloud waters, J. Geophys. Res., 99, 8231–8248, 1994. Braun, W., Herron, J. T., and Kahaner, D. K.: Acuchem: A computer program for modeling complex chemical reaction systems, Int. J. Chem. Kin., 20, 51–62, 1988. Chu, L. and Anastasio, C.: Formation of hydroxyl radical from the photolysis of frozen hydrogen peroxide, J. Phys. Chem. A, 109, 6264–6271, 2005. Donati, A.: Spectroscopic and kinetic investigations of halogen-containing radicals in the tropospheric aqueous phase, Ph.D. Dissertation, University of Leipzig, 2002. Ershov, B. G.: Kinetics, mechanism and intermediates of some radiation-induced reactions in aqueous solutions, Russian Chem. Rev., 73, 101–113, 2004. Matthew, B. M.: Chemical probe technique for the detection of oxidized halogen species in aqueous solution, Ph.D. Dissertation, University of California – Davis, 2002. Matthew, B. M. and Anastasio, C.: Determination of halogenated mono-alcohols and diols in water by gas chromatography with electron-capture detection, J. Chromatogr. A, 866, 65–77, 2000. Matthew, B. M. and Anastasio, C.: A chemical probe technique for the determination of reactive halogen species in aqueous solution: Part 1 – Bromide solutions, Atmos. Chem. Phys., 6, 2423–2437, 2006. Matthew, B. M., George, I., and Anastasio, C.: Hydroperoxyl radical (HO$_2)$ oxidizes dibromide radical anion (Br$_2$-) to bromine (Br$_2)$ in aqueous solutions: Implications for the formation of Br$_2$ in the marine boundary layer, Geophys. Res. Lett., 30, 2297–2301, 2003. Newberg, J. T.: Measurements of inorganic ion composition, UV-visible absorption and hydroxyl radical kinetics in marine particles from the northeasetrn Pacific Ocean, M. S. Thesis, University of California – Davis, 2003. Zafiriou, O. C., True, M. B., and Hayon, E.: Consequences of OH radical reaction in sea water: Formation and decay of Br$_2$- ion radical, in: Photochemistry of Environmental Aquatic Systems, edited by: Zika, R. G. and Cooper, W. J., American Chemical Society, Washington D.C., 89–105, 1987. Zhou, X. and Mopper, K.: Determination of photochemically produced hydroxyl radicals in seawater and freshwater, Mar. Chem., 30, 71–88, 1990.