International Humic Substances Society IHSS

The HS samples used in this work were obtained from the Standard and Reference Collection of HAs and FAs of the International Humic Substances Society (IHSS), with the exception of the HA from an alluvial soil. The origin and nature of HS, with the corresponding codes, abbreviations and concentrations used, are shown in Table 1. 

Humic (HA) and fulvic acids (FA) and Humin (HU) were isolated utilizing the standard method recommended by the International Humic Substances Society (IHSS). Their amounts were obtained by quantifying carbon in each fraction and in each step of the fractionation procedure. 

Standard materials were also investigated for comparison. These included two humic acids, one from Alfa Aesar (CAS 1415-93-6) obtained from an unknown source, and one from the International Humic Substances Society (IHSS) obtained from standard Elliot soil. IHSS fulvic acid from Elliot soil was also used for comparison. Humic acids are ubiquitous geologic contaminants present in archaeological materials that have been exposed to soil or groundwater, and are important comparative materials for surfaces that are to be (or in this case, have been) radiocarbon dated by the PCO-AMS technique. 

When the International Humic Substances Society (IHSS) was founded at a meting in the US Geological Survey in September 1981, it was decided to hold... 

Books have been written about HSs, which are the dominant fraction of natural organic matter (NOM). The International Humic Substances Society (IHSS) has been founded, but a common structure of a HS has not yet been widely accepted. The large variety of size, functional groups and origin makes researchers lives difficult and analytical methods remain complex and often lead to irreproducible results. The amount of literature available on HSs is extensive, but the quality of research done is often limited to the methods of analysis available and raw water samples used. Results are mostly incomparable due to the use of very different source materials and extraction methods. 

A fractal approach to the study of the chemistry and geochemistry of humic materials has a number of possible applications that the limited number of papers published on this property have only begun to consider. In the paragraphs below, a few possible examples are given. To fully realize the insights that a fractal approach could provide will require systematic study of a suite of carefully isolated and well-characterized humic substances. The International Humic Substances Society (IHSS) has such a collection of standard and reference humic materials that would be an ideal sample suite for this purpose [54, 55]. 

Humic acids do not occur alone in the environment. They occur in mixtures with amino acids, sugars, various aromatic and aliphatic acids, and other organic compounds, and/or associated with mineral components. In order to study the chemistry of humic substances, they must be first isolated. Because humic and fulvic acids are defined by the technique that is used for their extraction, and in order to get comparable results, it is particularly recommended to follow the isolation procedures used by the International Humic Substance Society (IHSS). 

Hayes, M. H. B., Dawson, J. E., Mortensen, J. L., Clapp, C. E., and Hausler, M. J. (1985). Comparisons of synthetic humic-like substances with soil humic acids. In Volunteered Papers, 2nd International Conference, International Humic Substances Society (Birmingham, 1984), Hayes, M. H. B., and Swift, R. S., eds., IHSS, University of Minnesota, St. Paul, pp. 

International Humic Substances Society (2008). Isolation of IHSS Samples. http //ihss. gatech.edu/ihss2/isolation.html. 

Clapp C. E., Hayes M. H. B., Senesi N., and Griffith S. M. (1996) Humic Substances and Organic Matter in Soil and Water Environments Characterization, Transformations, and Interactions. Proceedings of the International Conference of the International Humic Substances Society, University of the West Indies, St Augustine, Trinidad and Tobago, July 3-9, 1994. IHSS, St. Paul, MN, 493pp. 

D surface fractal dimension D mass fractal dimension HA humic acid NOM unfractionated natural organic matter saintle. IHSS International Humic Substances Society. 

The International Humic Substance Society was founded in 1981 to bring together scientists in the coal, soil, and water sciences with interests in humic substances. Recommended methods are available at www.ihss.gatech.edu. 

All measurements were performed in aqueous solution ([Pg.219]

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