Portal de Periódicos da CAPES

Gross Chemical Fractionation of Organic Matter

2016; Linguagem: Inglês

10.2134/agronmonogr9.2.c43

2156-3276

F. J. Stevenson,

Food Industry and Aquatic Biology

This chapter discusses three soil organic matter fractionation procedures. The first concerns the proximate analysis for estimating waxes, resins, hemicellulose, cellulose, and lignin-humus. The second describes the classical method for subdividing humus into the fractions referred to as humin, humic acid, fulvic acid, a-humus, and hymatomelanic acid. The third method gives a scheme for the subdivision of the fulvic acid fraction. The proximate analysis method applies a series of treatments to a single soil sample to dissolve specific classes of organic compounds from plant tissues. The fractionating humus method is based on the extraction of organic matter from soil with caustic alkali and the subdivision of the extracted material by partial precipitation with mineral acids, and by partial solubility in alcohol. The fulvic fraction of soil organic matter is separated by partial adsorption on activated charcoal and serial elution of the adsorbed material with 90% acetone, distilled water, and 0.5N sodium hydroxide.