Aquatic humic substances characterization

Watt BE, Clark NWE, Hayes MHB, Chipman JK, Skjemstad JO, Swift RS (1996) Aquatic humic substances from Pristine watersheds chemistry and postchlorination mutagenicity. In Clapp CE, Hayes MHB, Senesi N, Griffith SM (eds) Humic substances and organic matter in soil and water environments characterization, transformations and interactions. Proceedings of the 7th international conference IHSS, St. Augustine, Trinidad and Tobago, pp 389-390... 

Zhang X, Minear RA (2002) Characterization of high molecular weight disinfection byproducts resulting from chlorination of aquatic humic substances. Environ Sci Technol 36(19) 4033 038... 

Aiken, G. R. 1985. Isolation and concentration techniques for aquatic humic substances. In Humic Substances in Soil, Sediment and Water Geochemistry, Isolation, and Characterization (G. R. Aiken, D. M. McKnight, R. L. Wershaw, and P. MacCarthy, Eds.), pp. 363—385. 

Rice, J. A., and MacCarthy, P. (1989). Characterization of a stream sediment humin. In Influence of Aquatic Humic Substances on Fate and Treatment of Pollutants, Suffet, I. H., and MacCarthy, P, eds., ACS Advances Chemistry, Series, No. 219, American Chemical Society, Washington, D.C., pp. 41-54. 

Abbt-Braun, G., Lankes, U., and Frimmel, F. H. (2004). Structural characterization of aquatic humic substances— I he need for a multiple method approach. Aquat. Sci. 66,151-170. 

Sargentini, E., Jr., Rocha, J. C., Rosa, A. H., Zara, L. F., and dos Santos, A. (2001). Aquatic humic substances Molecular size fractionation and characterization of inner rearrangements after metal ions complexation. Quimica Nova 24(3), 339-344. 

Burba, P., Shkinev, V and Spivakov, B.Ya. (1995) On-line fractionation and characterization of aquatic humic substances by means of sequential-stage ultrafiltration. Fresenius J. Anal. Chem., 351, 74-82. 

Ikeda K., Arimura R., Echigo S., Shimizu Y., Minear R. A., and Matsui S. (1999) The fractionation/concentration of aquatic humic substances by the sequential membrane system and their characterization with mass spectrometry. Water Set Technol. 42, 383-390. 

The final product should be free from chemical impurities, which hinder characterization of the isolated material, and should be in a form that can resist biological and chemical degradation. Many options are available for isolating and concentrating these compounds. Each method has advantages and disadvantage, and best results can be obtained by adopting a combination of techniques It is the purpose of this chapter to critically discuss and evaluate various ethods commonly used to isolate and concentrate aquatic humic substances. 

Malcolm, R. L., Wershaw, R. L., Thurman, E. M., Aiken, G. R., Pinckney, D. J., and Kaakinen, J. (1981). Reconnaissance sampling and characterization of aquatic humic substances at the Yuma Desalting Test Facility, Arizona. U.S. Geol. Surv. Water Resour. Invest., 81-42. 

J. Peuravuori, K. Pihlaja (1999). Characterization of aquatic humic substances. In J. Keskitalo, P. Eloranta (Eds), (pp. 11-39). Limnology of Humic Waters. Backhuys Publishers, Leiden, The Netherlands. 

Chemical characterization of DOM has been studied extensively, providing a wealth of information regarding its chemical properties [17,20,25,60,64-89]. CDOM is usually characterized as aquatic humic substances, such as humic and fulvic acids, owing to the presence of multiple double bonds in aromatic, aldehyde, and ketone groups. Isolation of humic substances involves their separation by adsorption on macroporous resins (e.g., XAD-8 or XAD-4) and elution at various pH [90]. Humic acids are soluble above a pH of 2, while fulvic acids are soluble at any pH. Solid phase extraction (SPE) onto Cig resin is also employed to isolate CDOM [44,73]. Amador and coworkers have shown that... 

Burba, P., Jakubowski, B., Kuckuk, R., Kiillmer, K., and Heumann, K. G., Characterization of aquatic humic substances and their metal complexes by immobilized metal-chelate affinity chromatography on iron (lll)-loaded ion exchangers, Fresenius J. Anal Chem., 368, 689-696, 2000. 

Fig. 126. Sequence of steps for isolating and characterizing aquatic humic substances...

As an approach to investigating the complex chemistry of natural foams, humic substances (compounds sufficiently nonpolar at pH 2.0 to be isolated by reverse phase on XAD-8 and recovered in 0.1 N sodium hydroxide) were isolated from aquatic foam and associated stream water for chemical characterization and investigations into surfactant behavior. Humic substances were chosen because they represent natural organic compounds present in natural waters that are sufficiently nonpolar at pH 2.0 to be isolated by XAD-8 adsorption. As surfactants also possess moderately nonpolar characteristics it follows that humic substances may contain a significant surfactant component. We hypothesized that foam would be enriched in humic substances compared to stream samples and would show increased hydrophobicity, aliphaticity, and decreased carboxylation in order to sustain surface-active behavior. 

Tremendous work has been done on the characterization of humic substances in the aquatic environment (2,19,20) and much analytical data on the concentration of humic substances in natural waters is reported (2,21- 5). Special attention has been paid to the physico-chemical processes governing behaviour of metals and dissolved organic matter during estuarine mixing (6,26-28). 

J.F. Power, D.K. Sharma, C.H. Langford, R. Bonneau, J. Joussot-Dubien (1987). Laser flash photolytic studies of a well-characterized soil humic substance. In R.G. Zika, W.J. Cooper (Eds), Photochemistry of Environmental Aquatic Systems (pp. 157-173). American Chemical Society, Washington. 

Gadel, F. and Bmchet, A., Apphcation of pyrolysis-gas chromatography-mass spectroscopy to the characterization of humic substances resulting from decay of aquatic plants in sediments and waters. Water Res., 21, 1195-1206, 1987. 

Heitz, A., loll, C., Alexander, R., and Kagi, R. I., Characterization of aquatic natural organic matter in some Western Australian drinking water sources. In Understanding and Managing Organic Matter in Soils, Sediments and Waters, Swift, R. S. and Spark, K. M., Eds., International Humic Substances Society, Adelaide, Australia, 2001. 

Power JE, Sharma DK, Langford CH, Bonneau R, Jossert-Dubien J (1987) Laser flash photolysis studies of a weU-characterized soil humic substance. In Zika RG, Cooper WJ (eds) Photochemistry of environmental aquatic systems. ACS Symposium Series 237, American Chemical Society, Washington DC, p 157 Zepp RG, Braim AM, Hoigne J, Leenheer JA (1987) Environ Sci Tech 21 485 Swallow AJ (1969) Nature 222 369... 

After T720 was tentatively characterized as an aquated electron with nitrous oxide and electron transfer studies, the quantum yield for the production of the aquated electron In dilute natural waters containing dissolved organic matter and In humic substance extract was measured by the comparlslon method. In this method the literature value for the extinction coefficient of the solvated electron at 720 nm was used (21). The excited state absorption of T720 was measured. These were used In algebraic ratio to an actlnomlter for which a quantum yield had already been thoroughly determined. 

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