Abstract
The reactivity of 2 µM molecular iodine in seawater toward various organic compounds containing aromatic, α-keto, amino, olefinic and sugar functional groups was investigated. More detailed studies have been made of the reduction kinetics with salicylic acid, α-ketoglutaric acid and the polypeptide oxidized glutathione, particularly to establish whether variation over the pH range 4–9 would provide a similar reduction reactivity or “fingerprint” to that of molecular iodine added to natural seawater. The data indicates that compounds with only one functional group react with first order kinetics whereas compounds with multiple functional groups show more complex behaviour. Kinetic and thermodynamic modelling indicates that HOI is the main iodine species reacting with organic matter at seawater pH of 8.2. Based on the pH “fingerprints”, peptides and compounds containing carbonyl or α-keto groups are the key reductants of molecular iodine added to seawater. These compounds form C-I and N-I bonds which can allow for a rich organic iodine chemistry in seawater. The model compound results are discussed in relation to oceanic processes.
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References
Alouini, Z. and Seux, R. (1987) Kinetics and mechanisms of hypochlorite oxidation of α-amino acids at the time of water disinfection.Water Res. 21, 335–343.
Bailey, G. S. (1990) In vitro labelling. B. Proteins. InRadio-Isotopes in Biology — A Practical Approach (ed. R. J. Slater). IRL Press, Oxford, U.K., pp. 191–205.
R. Barkley, A. and Thompson, T. G. (1960) Determination of chemically combined iodine in sea water by amperometric and catalytic methods.Anal. Chem. 32, 154–158.
Benner, R., Pakulski, J. D., McCarthy, M., Hedges, J. I., and Hatcher, P. G. (1993) Bulk chemical characteristics of dissolved organic matter in the ocean.Science 255, 1561–1564.
Buss, W. C. and Taylor, J. E. (1960) The iodination of phenols. II. The design and construction of a reliable stirred flow reactor and its use in kinetic studies on 2,4-dichlorophenol.J. Amer. Chem. Soc. 82, 5991–5996.
Deuser, W. G., Ross, E. H., and Anderson, R. F. (1981) Seasonality in the supply of sediment to the deep Sargasso Sea and implications for the rapid transfer of matter to the deep ocean.Deep-Sea Res. 28, 495–505.
Eigen, M. and Kustin, K. (1962) The kinetics of halogen hydrolysis.J. Am. Chem. Soc. 84, 1355–1361.
Eppley, R. W., Renger, E. H., and Williams, P. M.: Chlorine reactions with seawater constituents and the inhibition of photosynthesis of natural marine phytoplankton.Est. Coastal Mar Res. 4, 147–161.
Grovenstein, Jr., E., Aprahamian, N. S., Bryan, C. J., Gnanapragasam, N. S., Kilby, D. C., McKelvey, J. M., and Sullivan, R. J. (1973) Aromatic halogenation. IV. Kinetics and mechanism of iodination of phenol and 2,6-dibromophenol.J. Am. Chem. Soc. 95, 4261–4270.
Harvey, G. R. (1980) A study of the chemistry of iodine and bromine in marine sediments.Mar. Chem. 8, 327–332.
Hogfeldt, E. (1982)Stability Constants of Metal-Ion Complexes. Part A: Inorganic Ligands. Pergamon Press, New York; IUPAC Chemical Data Series, No. 21, 310 pp.
Ingold, C. K. (1963)Structure and Mechanism in Organic Chemistry. G. Bell & Sons, London. 828 pp.
Jickells, T. D., Deuser, W. G., and Belastock, R. A. (1990) Temporal variations in the concentrations of some particulate elements in the surface waters of the Sargasso Sea and their relationship to deep-sea fluxes.Mar. Chem. 29, 203–219.
Kennedy, H. A. and Elderfield, H. (1987a) Iodine diagenesis in pelagic deep-sea sediments.Geochim. Cosmochim. Acta 51, 2489–2504.
Kennedy, H. A. and Elderfield, H. (1987b) Iodine diagenesis in non-pelagic deep-sea sediments.Geochim. Cosmochim. Acta 51, 2505–2514.
Kieber, R. J., Zhou, X., and Mopper, K. (1990) Formation of carbonyl compounds from UV-induced photodegradation of humic substances in natural waters: Fate of riverine carbon in the sea.Limnol. Oceangr. 35, 1503–1515.
Klick, S. and Abrahmsson, K. (1992) Biogenic volatile iodated hydrocarbons in the ocean.J. Geophys. Res. 97, 683–687.
Lee, C. and Wakeham, S. G. (1988) Organic matter in seawater: Biogeochemical processes. InChemical Oceanography, Vol. 9 (ed. J. P. Riley), Academic Press, New York, Ch. 49, pp. 1–51.
Luther III, G. W. and Campbell, T. (1991) Iodine speciation in Black Sea waters.Deep Sea Res. 38, (Suppl. 2A), S875-S882.
Luther III, G. W., Branson Swartz, C., and Ullman, W. J. (1988) Direct determination of iodide in seawater by cathodic stripping square wave voltammetry.Anal. Chem. 60, 1721–1724.
Luther III, G. W., Ferdelman, T., Culberson, C. H., Kostka, J., and Wu, J. (1991a) Iodine chemistry in the water column of the Chesapeake Bay: Evidence for organic iodine forms.Est. Coastal Shelf Sci. 32, 267–279.
Luther III, G. W., Ferdelman, T. G., Kostka, J. E., Tsamakis, E. J., and Church, T. M. (1991b) Temporal and Spatial variability of reduced sulfur species (FeS2, S2O 2−3 ) and porewater parameters in salt marsh sediments.Biogeochem. 14, 57–88.
Luther III, G. W., Wu, J., and Cullen, J. (1995) Redox chemistry of iodine in seawater: Frontier molecular orbital theory considerations. ACS Advances in Chemistry series, Vol. 244,Aquatic Chemistry: Interfacial and Interspecies Processes (eds. C. P. Huang, C. R. O'Melia, J. J. Morgan) pp. 135–155
Miyake, Y. and Tsunogai, S. (1963) Evaporation of iodine from the ocean.J. Geophys. Res. 68, 3989–3993.
Mopper, K. and Stahovec, W. L. (1986) Sources and sinks of low molecular weight organic carbonyl compounds in seawater.Mar. Chem. 19, 305–321.
Morgan, K. J. (1954) Some reactions of inorganic iodine compounds.Quarterly Revs. 8, 123–146.
Noller, C. R. (1966)Text-Book of Organic Chemistry. 3rd ed. W.B. Saunders, London, 760 pp.
Palmer, D. A. and Lietzke, M. H. (1982) The equilibria and kinetics of iodine hydrolysis.Radiochimica Acta 31, 37–44.
Richardson, L. B., Burton, D. T., Helz, G. R., and Rhoderick, J. C. (1981) Residual oxidant decay and bromate formation in chlorinated and ozonated sea-water.Water Res. 15, 1067–1074.
Schofield, K., Grimmett, M. R., and Keene, B. R. T. (1976)Hetero Aromatic Nitrogen Compounds: The Azoles. Cambridge Univ. Press, Cambridge, pp. 55–58.
Shimmield, G. B. and Pederson, T. F. (1990) The geochemistry of reactive trace metals and halogens in hemipelagic continental margin sediments.Reviews in Aquatic Sci. 3, 255–279.
Stanbury, D. M. (1989) Reduction potentials involving free radicals in aqueous solution. InAdvances in Inorganic Chemistry (ed. A. G. Sykes), Vol. 33, pp. 69–138.
Stumm, W. and Morgan, J. J. (1981)Aquatic Chemistry. John Wiley and Sons, New York, 780 pp.
Sugawara, K. and Terada, K. (1958) Oxidised iodine in seawater.Nature 182, 250–251.
Truesdale, V. W. (1974) The chemical reduction of molecular iodine in seawater.Deep-Sea Res. 21, 761–766.
Truesdale, V. W. (1975) “Reactive” and “unreactive” iodine in seawater — A possible indication of an organically bound iodine fraction.Mar. Chem. 3, 111–119.
Truesdale, V. W. (1978) The automatic determination of iodate- and total-iodine in seawater.Mar. Chem. 6, 253–273.
Truesdale, V. W. (1993) The reduction of molecular iodine by seawater modelled as a system of first order reactions.Mar. Chem. 42, 147–166.
Truesdale, V. W. and Moore, R. M. (1992) Further studies on the chemical reduction of molecular iodine added to seawater.Mar. Chem. 40, 199–213.
Truesdale, V. W., Canosa-Mas, C. E., and Luther III, G. W. (1995) Disproportionation and reduction of molecular iodine added to seawater.Mar. Chem. in press.
Truesdale, V. W., Luther III, G. W., and Canosa-Mas, C. (1995) Molecular iodine reduction in seawater: An improved rate equation considering organic compounds.Mar. Chem. 48, 143–150.
Ullman, W. J., Luther III, G. W., de Lange, G., and van der Sloot, H. (1990) Iodine chemistry in deep anoxic basins and overlying waters of the Mediterranean Sea.Mar. Chem. 31, 153–170.
Upstill-Goddard, R. C. and Elderfield, H. (1988) The role of diagenesis in the estuarine budgets of iodine and bromine.Continental Shelf Res. 8, 405–430.
Vairavamurthy, A. and Mopper, K. (1987) Geochemical formation of organosulphur compounds (thiols) by addition of H2S to sedimentary organic matter.Nature 329, 623–625.
Westall, J. C., Zachary, J. L., and Morel, F. F. M. (1976) MINEQL, a computer program for the calculation of chemical equilibrium composition of aqueous systems. Technical Note 18, Dept. Civil Engineering, MIT.
William, D. S. and Wendy, D. S. (1979) Kinetics and mechanism of the decomposition of N-chloroalanine in aqueous solution.J. Am. Chem. Soc. 13, 446–451.
Wong, G. T. F. and Oatts, T. J. (1984) Dissolved organic matter and the dissipation of chlorine in estuarine water and seawater.Water Res. 18, 501–504.
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Truesdale, V.W., Luther, G.W. Molecular iodine reduction by natural and model organic substances in seawater. Aquat Geochem 1, 89–104 (1995). https://doi.org/10.1007/BF01025232
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DOI: https://doi.org/10.1007/BF01025232