Humins

Humin-saure, /. humic acid, -stoff, m., -sub-stani, /. humic (or humous) substance. Hummel, /. bumblebee. 

Humic substances in sediments and soils have commonly been, defined as heteropolycondensates of decomposing plant and animal detritus 46. For lack of a better structural definition, these macromolecular substances have been divided into three categories fulvic acids and humic acid and humin. Fulvic acids and humic acids are soluble in dilute alkaline solutions, whereas humin is insoluble. 

Various destructive and non-destructive methods of analysis have been tested and H-l and C-13 NMR have, among other techniques provided valuable structural information on soluble humic acids and fulvic acids 48, Humin, on the other hand has withstood detailed non-destructive analysis. 

H NMR 38,39,42, 50-55 Hole capacity constant 205 Homogeneous distribution of correlation times 37 Humic acids 17 Humidity of plastics 119 Humins 17 Hydrogen bond 200 Hydrophilic 191, 194, 206... 

Residual. This fraction mainly contains primary and secondary minerals, which hold elements within their crystal structure. This fraction also contains trace elements remained from the extraction of all previous fractions (e.g., humin bound). These metals/trace elements are not expected to be released into soil solutions over a reasonable time span under conditions normally encountered in nature. 

Clay mineral bound, humin bound, and residual fractions... 

Fig. 6. Relationship between the log Koc for phenanthrene sorption and the polarity index of humic acids and humin, sequentially extracted from a soil. F-l, F-4, F-7, and F-9 are the first, fourth, seventh, and nineth extracted humic acids, respectively. 0.005, 0.05, and 0.5 ig mL 1 are selected liquid-phase equilbrium concentration of phenathrene (Kang and Xing 2005).

Almendros G, Guadalix G, Gonzalez-Vila F, Martin F (1996) Preservation of aliphatic macromolecules in soil humins. Org Geochem 24 651-659... 

Kang S, Amarasiriwardena D, Veneman P, Xing B (2003) Characterization of ten sequentially extracted humic acids and a humin from a soil in western Massachusetts. Soil Sci 168 880-887... 

Kang S, Xing B (2005) Phenanthrene sorption to sequentially extracted soil humic acids and humins. Environ Sci Technol 39 130-140... 

Lichtfouse E, Leblond C, DaSilva M, Behar F (1998b) Occurrence of biomarkers and straight chain biopolymers in humin implication for the origin of soil organic matter. Naturwissenschaften 85 497-501... 

The octanol-water partition coefficient KqW provides a direct estimate of hydrophobicity or of partitioning tendency from water to organic media such as lipids, waxes and natural organic matter such as humin or humic acid. It is invaluable as a method of estimating KoC, the organic carbon-water partition coefficient, the usual correlation invoked being that of Karickhoff (1981)... 

Sapsucker Woods S.W. soil, S.W. ethyl ether extracted soil, humin, oxidized... 

Transformation of the initially deposited remains of living organisms started in the water columns and in the upper layers of bottom sediments of ancient seas. Random polymerization and condensation reactions of degraded biopolymers are believed to have formed the initial geopolymers, which contain humin, fulvic and humic acids. Until now these compounds (very typical for soil humus as well) are... 

Many researchers have attempted to unravel the mystery of the structure of humus. One approach has been to isolate fractions by extracting humus using various extraction procedures. These procedures result in the isolation of three or more fractions humic acid, fulvic acid, and humin. Humic material is isolated from soil by treating it with alkali. The insoluble material remaining after this treatment is called humin. The alkali solution is acidified to a pH of 1.0 and the precipitate is called humic acid, while the soluble... 

Soil microorganisms degrade methoprene rapidly and extensively (27). The hydroxy ester was isolated as a minor metabolite over 50% of the applied dose was evolved as 1 C02. Radioactivity from [5-1 0]methoprene incorporated into the humic acid, fulvic acid, and humin fractions of soil. 

The chemical structures of the amino acids found in soil-solids are shown in Fig. 6 [25] while the quantities of amino acids found in HS extracted from various solid phases are represented in Fig. 7 (data were collected from Ghosh and Schnitzer [37] and Schnitzer et al. [38]). High levels of amino acid nitrogen were found in HA, FA, and humin fractions, indicating incorporation of common acidic and some neutral amino acids, particularly glycine, alanine, and valine. 

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