Original scientific paper

Humic Acids – Are They Natural Products?

Petr Zuman
Elinore B. Rupp

Abstract

Alkaline cleavage of soil organic matter was studied by following the changes in absorbance at 250–270 nm, but particularly using differential pulse polarography. The measurement of peak currents obtained by the latter technique allowed to follow changes in concentration of CH3Oand HO-substituted benzaldehydes as well as of α,β-unsaturated ketones with time directly in the suspension of soil. Kinetics of the cleavage of the organic materials from soil and in particular its pH-dependence, were similar to that of cleavage of lignin, but different from those obtained with samples of humic acids. Based on this comparison and on discussion of chemical processes taking place during procedures used for isolation of humic acids from soils and waters, it is strongly indicated that humic acids are man-made macromolecular species rather than natural products.

Keywords

soils; lignins; humic acids; alkaline cleavage; kinetics

Hrčak ID:

2602

URI

https://hrcak.srce.hr/2602

Publication date:

22.4.2006.

Article data in other languages: croatian

Visits: 2.496 *