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Measurement of the Molecular Size of a Sodium Humate Fraction*

Published online by Cambridge University Press:  06 March 2019

R. L. Wershaw
Affiliation:
U. S. Geological Survey Denver, Colorado 80225
S. J. Heller
Affiliation:
U. S. Geological Survey Denver, Colorado 80225
D. J. Pinckney
Affiliation:
U. S. Geological Survey Denver, Colorado 80225
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Extract

Many of the chemical and physical interactions that take place in natural soil-water systems are strongly influenced by the presence of natural organic polyelectrolytes. The most common of these organic polyelectrolytes is humic acid, which is defined as the alkali soluble, acid insoluble fraction of soil organic matter. Over a hundred years of experimental data have demonstrated that a wide variety of different materials having different physical and chemical properties fit this definition. If we are to make any progress in understanding the role of humic materials in soil-water systems, then we must have a classification system which, as far as possible, provides a unique taxonomic definition for each separate molecular species that falls into the category of humic acid.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1969

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Footnotes

*

Publication authorized by the Director, U.S. Geological Survey.

References

1. Mehta, N. C., Dubach, P., and Deuel, H., “Untersuchungen uber die molekulargewichtsverteilung von huminstoffen durch gelfiltration an Sephadex”, Z Pflanaenernahr, Dung., Bodenkunde Vol. 102, p. 128137, 1963.Google Scholar
2. Piret, E. L., White, R. G., Walther, H. C. and Madden, A. J., “Some physico-chemical properties of peat humic acids”, Scientific Proceedings of the Royal Dublin Society, Vol. 1A p. 6979, 1960.Google Scholar
3. Gjessing, E. T., “Use of Sephadex gel for the estimation of molecular weight of humic substances in natural water”, Nature, Vol. 208, p. 10911092, 1965.Google Scholar
4. Bailly, J. R., “Fractionnement des acides humiques suivant leur encombrement moleculaire. Appreciation sommaire de quelques poids moleculaires privilegies”, Acad. Sci. (Paris) Compte Rendus, Vol. 264, p. 564566, 1967.Google Scholar
5. Wershaw, R. L., Burcar, P. J., Sutula, C. L., and Wiginton, B. J., “Sodium humate solution studied with small-angle x-ray scattering”, Sci. Vol. 157, no.3795, p. 14291431, 1967.Google Scholar
6. Lindqvist, Ingvar, “Adsorption effects in gel filtration of humic acid”, Acta Chem. Scand., Vol.21, p. 25642566, 1967.Google Scholar
7. Posner, A. M., “Importance of electrolyte in the determination of molecular weights by Sephadex gel filtration with especial reference to humic acid”, Nature, Vol. 198, p. 11611163, 1963.Google Scholar
8. Kratky, O., “X-ray small angle scattering with substances of biological interest in dilute solutions”, Progress in Biophysics, Vol. 13, p. 105173, 1963.Google Scholar
9. Wershaw, R. L. and Burcar, P. J., “Physical- Chemical properties of naturally occurring polyelectrolytes — I Sodium humate”, Proceedings of the Third Annual American Water Resources Conference, p. 351364, 1967.Google Scholar
10. Beeman, W. W., Kaesberg, P., Anderegg, J. W. and Webb, M. B., “Size and Particles and Lattice Defects, Handbuch der Physik, Vol. 32, p. 321442, 1957.Google Scholar
11. Guinier, A. and Foumet, G., “Small-Angle Scattering of X-rays”, Wiley, New York, 1955.Google Scholar