ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-843-2010 Hydroxyl radical reactivity at the air-ice interface Kahan T. F. 1 Zhao R. 1 Donaldson D. J. 1 2 Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, M5S 3H6 Ontario, Canada Department of Physical and Environmental Sciences, University of Toronto, Scarborough, Canada 26 01 2010 10 2 843 854 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/10/843/2010/acp-10-843-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/843/2010/acp-10-843-2010.pdf

Hydroxyl radicals are important oxidants in the atmosphere and in natural waters. They are also expected to be important in snow and ice, but their reactivity has not been widely studied in frozen aqueous solution. We have developed a spectroscopic probe to monitor the formation and reactions of hydroxyl radicals in situ. Hydroxyl radicals are produced in aqueous solution via the photolysis of nitrite, nitrate, and hydrogen peroxide, and react rapidly with benzene to form phenol. Similar phenol formation rates were observed in aqueous solution and bulk ice. However, no reaction was observed at air-ice interfaces, or when bulk ice samples were crushed prior to photolysis to increase their surface area. We also monitored the heterogeneous reaction between benzene present at air-water and air-ice interfaces with gas-phase OH produced from HONO photolysis. Rapid phenol formation was observed on water surfaces, but no reaction was observed at the surface of ice. Under the same conditions, we observed rapid loss of the polycyclic aromatic hydrocarbon (PAH) anthracene at air-water interfaces, but no loss was observed at air-ice interfaces. Our results suggest that the reactivity of hydroxyl radicals toward aromatic organics is similar in bulk ice samples and in aqueous solution, but is significantly suppressed in the quasi-liquid layer (QLL) that exists at air-ice interfaces.

 References Anastasio, C. and Chu, L.: Photochemistry of Nitrous Acid (HONO) and Nitrous Acidium Ion (H<sub>2</sub>ONO$^+$) in Aqueous Solution and Ice, Environ. Sci. Technol., 43(4), 1108–1114, 2009. Anastasio, C., Galbavy, E. S., Hutterli, M. A., et al.: Photoformation of hydroxyl radical on snow grains at Summit, Greenland, Atmos. Environ., 41(24), 5110–5121, 2007. Ardura, D., Kahan, T. F., Donaldson, D. J.: Self-association of naphthalene at the air-ice interface, J. Phys. Chem. A, 113: 7353–7359, 2009. Aubin, D. G. and Abbatt, J. P. D.: Interaction of NO<sub>2</sub> with hydrocarbon soot: Focus on HONO yield, surface modification, and mechanism, J. Phys. Chem. A, 111(28), 6263–6273, 2007. Carrera, G., Fernandez, P., Vilanova, R. M., et al.: Persistent organic pollutants in snow from European high mountain areas, Atmos. Environ., 35(2), 245–254, 2001. Chu, L. and Anastasio, C.: Quantum yields of hydroxyl radical and nitrogen dioxide from the photolysis of nitrate on ice, J. Phys. Chem., 107, 9594–9602, 2003. Chu, L. and Anastasio, C.: Formation of hydroxyl radical from the photolysis of frozen hydrogen peroxide, J. Phys. Chem. A, 109, 6264–6271, 2005. Chu, L. and Anastasio, C.: Temperature and wavelength dependence of nitrite photolysis in frozen and aqueous solutions, Environ. Sci. Technol., 41(10), 3626–3632, 2007. Cincinelli, A., Stortini, A. M., Checchini, L., et al.: Enrichment of organic pollutants in the sea surface microlayer (SML) at Terra Nova Bay, Antarctica: influence of SML on superfacial snow composition, J. Environ. Monitor., 7(12), 1305–1312, 2005. Clifford, D., Bartels-Rausch, T., Donaldson, D. J.: Suppression of aqueous surface hydrolysis by monolayers of short chain organic amphiphiles, Phys. Chem. Chem. Phys., PCCP 9, 1362–1369, 2007. Compoint, M., Toubin, C., Picaud, S., et al.: Geometry and dynamics of formic and acetic acids adsorbed on ice, Chem. Phys. Lett., 365(1–2), 1–7, 2002. Cotter, E. S. N., Jones, A. E., Wolff, E. W., et al.: What controls photochemical NO and NO<sub>2</sub> production from Antarctic snow? Laboratory investigation assessing the wavelength and temperature dependence, J. Geophys. Res., 108, 8-1–8-10, 2003. Daly, G. L. and Wania, F.: Organic contaminants in mountains, Environ. Sci. Technol., 39(2), 385–398, 2005. Domine, F., Albert, M., Huthwelker, T., et al.: Snow physics as relevant to snow photochemistry, Atmos. Chem. Phys., 8(2), 171–208, 2008. Domine, F. and Shepson, P. B.: Air-snow interactions and atmospheric chemistry, Science, 297 1506–1510, 2002. Dubowski, Y., Colussi, A. J., Boxe, C., et al.: Monotonic increase of nitrite yields in the photolysis of nitrate in ice and water between 238 and 294 K, J. Phys. Chem. A, 106(30), 6967–6971, 2002. Dubowski, Y., Colussi, A. J., and Hoffmann, M. R.: Nitrogen dioxide release in the 302 nm band photolysis of spray-frozen aqueous nitrate solutions. Atmospheric implications, J. Phys. Chem. A, 105, 4928–4932, 2001. Dubowski, Y. and Hoffmann, M. R.: Photochemical transformations in ice: Implications for the fate of chemical species, Geophys. Res. Lett., 27, 3321–3324, 2000. Febo, A., Perrino, C., Gherardi, M., et al.: Evaluation of a High-Purity and High-Stability Continuous Generation System for Nitrous-Acid." Environ. Sci. Technol., 29(9): 2390–2395, 1995. Fernandez, P., G. Carrera, Grimalt, J. O., et al.: Factors governing the atmospheric deposition of polycyclic aromatic hydrocarbons to remote areas." Environ. Sci. Technol., 37(15), 3261–3267, 2003. Franz, T. P. and Eisenreich, S. J.: Accumulation of polychlorinated biphenyls and polycyclic aromatic hydrocarbons in the snowpack of Minnesota and Lake Superior." Journal of Great Lakes Research 26(2), 220–234, 2000. Galbavy, E. S., Anastasio, C., Lefer, B. L., et al.: Light penetration in the snowpack at Summit, Greenland: Part I – Nitrite and hydrogen peroxide photolysis, Atmos. Environ., 41(24), 5077–5090, 2007. Grannas, A. M., Bausch, A. R., et al.: Enhanced aqueous photochemical reaction rates after freezing, J. Phys. Chem. A, 111(43), 11043–11049, 2007a. Grannas, A. M., Jones, A. E., Dibb, J., et al.: An overview of snow photochemistry: evidence, mechanisms and impacts, Atmos. Chem. Phys., 7(16), 4329–4373, 2007b. Herbert, B. M. J., Villa, S., et al.: Chemical interactions with snow: Understanding the behavior and fate of semi-volatile organic compounds in snow, Ecotoxicology and Environmental Safety, 63(1), 3–16, 2006. Jacobi, H. W., Annor, T., Quansah, E., et al.: Investigation of the photochemical decomposition of nitrate, hydrogen peroxide, and formaldehyde in artificial snow, J. Photochem. Photobiol., 179(3), 330–338, 2006. Jaffrezo, J. L., M. P. Clain, and Masclet, P.: Polycyclic Aromatic-Hydrocarbons in the Polar Ice of Greenland – Geochemical Use of These Atmospheric Tracers, Atmos. Environ., 28(6), 1139–1145, 1994. Kahan, T. F. and Donaldson, D. J.: Photolysis of polycyclic aromatic hydrocarbons on water and ice surfaces, J. Phys. Chem. A, 111, 1277–1285, 2007. Kahan, T. F. and Donaldson, D. J.: Heterogeneous ozonation kinetics of phenanthrene at the air-ice interface, Environ. Res. Lett., 3, 045006z, doi:10.1088/1748-9326/3/4/045006 , 2008. Kahan, T. F., Reid, J. P., and Donaldson, D. J.: Spectroscopic probes of the quasi-liquid layer on ice, J. Phys. Chem. A, 111(43), 11006–11012, 2007. Kahan, T. F. and Donaldson, D. J.: Benzene photolysis at air-ice interfaces: Implications for the fate of organic pollutants in the winter, in preparation, 2010. Kahan, T. F., Zhao, R., Jumaa, K. B., et al.: Anthracene Photolysis in Aqueous Solution and Ice: Photon Flux Dependence and Comparison of Kinetics in Bulk Ice and at the Air-Ice Interface, Environ. Sci. Technol., in press, 2010. Klan, P. and Holoubek, I.: Ice (photo)chemistry. Ice as a medium for long-term (photo)chemical transformations – environmental implications, Chemosphere, 46, 1201–1210, 2002. Klan, P., Klanova, J., Holoubeket, I., et al.: Photochemical activity of organic compounds in ice induced by sunlight irradiation: The Svalbard project." Geophys. Res. Lett., 30, 46-1–46-4, 2003. Klanova, J., Klan, P., Heger, D., et al.: Comparison of the effects of UV, H<sub>2</sub>O<sub>2</sub>/UV and $\gamma\alpha\mu\mu\alpha$-irradiation processes on frozen and liquid water solutions of monochlorophenols, Photochem. Photobiol. Sci., 2, 1023–1031, 2003a. Klanova, J., Klan, P., Nosek, J., et al.: Environmental ice photochemistry: Monochlorophenols, Environ. Sci. Technol., 37, 1568–1574, 2003b. Lee, C. W., Lee, P. R., Kim, Y. K., et al.: Mechanistic study of proton transfer and H/D exchange in ice films at low temperatures (100–140 K), J. Chem. Phys., 127, 084701, doi:10.1063/1.2759917, 2007. Masclet, P., Hoyau, V., Jaffrezo, J. L., et al.: Polycyclic aromatic hydrocarbon deposition on the ice sheet of Greenland. Part I: Superficial snow, Atmos. Environ., 34(19), 3195–3207, 2000. Matykiewiczova, N., Kurkova, R., Klanova, J., et al.: Photochemically induced nitration and hydroxylation of organic aromatic compounds in the presence of nitrate or nitrite in ice, J. Photochem. Photobiol., 187(1), 24–32, 2007. Melnikov, S., Carroll, J., Gorshkov, A., et al.: Snow and ice concentrations of selected persistent pollutants in the Ob-Yenisey River watershed, Sci. Total Environ., 306(1–3), 27–37, 2003. Mmereki, B. T. and Donaldson, D. J.: Direct observation of the kinetics of an atmospherically important reaction at the air-aqueous interface, J. Phys. Chem. A, 107, 11038–11042, 2003. Pan, X., Bass, A. D., Jay-Gerin, J.-P., and Sanche, L.: A mechanism for the production of hydrogen peroxide and the hydroperoxyl radical on icy satellites by low-energy electrons, Icarus, 172, 521–525, 2004. Qiu, R., Green, S. A., Honrath, R. E., et al.: Measurements of $J$(NO<sub>3</sub>)(-) in snow by nitrate-based actinometry, Atmos. Environ., 36(15–16), 2563–2571, 2002. Ram, K. and Anastasio, C.: Photochemistry of phenanthrene, pyrene, and fluoranthene in ice and snow, Atmos. Environ., 43, 2252–2259, 2009. Schrimpff, E., Thomas, W., Herrmann, R., et al.: Regional Patterns of Contaminants (Pah, Pesticides and Trace-Metals) in Snow of Northeast Bavaria and Their Relationship to Human Influence and Orographic Effects, Water Air Soil Poll., 11(4), 481–497, 1979. Slater, J. F., Currie, L. A., Dibb, J. E., et al.: Distinguishing the relative contribution of fossil fuel and biomass combustion aerosols deposited at Summit, Greenland through isotopic and molecular characterization of insoluble carbon, Atmos. Environ., 36(28), 4463–4477, 2002. Stella, L., Seraglia, R., Sturaro, A., et al.: On the photochemical oxidation of benzene and its relevance at environmental level, Rapid Communications in Mass Spectrometry, 22(2), 257–260, 2008. Tubaro, M., Marotta, E., Seraglia, R., et al.: Atmospheric pressure photoionization mechanisms. 2. The case of benzene and toluene, Rapid Comm. Mass Spectrom., 17(21), 2423–2429, 2003. Vione, D., Falletti, G., Maurino, V., et al.: Sources and sinks of hydroxyl radicals upon irradiation of natural water samples, Environ. Sci. Technol., 40(12), 3775–3781, 2006. Wang, X. P., Xu, B. Q., Kang, S. C., et al.: The historical residue trends of DDT, hexachlorocyclohexanes and polycyclic aromatic hydrocarbons in an ice core from Mt. Everest, central Himalayas, China, Atmos. Environ., 42(27), 6699–6709, 2008a. Wang, X. P., T. D. Yao, et al. (2008b). "The recent deposition of persistent organic pollutants and mercury to the Dasuopu glacier, Mt. Xixiabangma, central Himalayas, Sci. Total Environ., 394(1), 134–143. Zheng, W., Jewitt, D., and Kaiser, R. I.: Formation of hydrogen, oxygen, and hydrogen peroxide in electron-irradiated crystalline water ice, The Astrophysical Journal, 639, 534–548, 2006.