Increased use of humic substances in agriculture has generated intense interest among producers, consumers, and regulators for an accurate and reliable method to quantify humic acid (HA) and fulvic acid (FA) in raw ores and products. Here we present a thoroughly validated method, the new standardized method for determination of HA and FA contents in raw humate ores and in solid and liquid produ...

Humic acids are complex, partly macromolecular, yellow-brownish substances occurring in soils, waters and sediments. In order to bring some light on their molecular structure, crop humic acids were cleaved by alkaline hydrolysis (KOH). The products were fractionated by thin layer chromatography to give mono-alcohols which were analysed as acetate derivatives by gas chromatography coupled to mas...

REFERENCIAS Y ENLACES [1] F. J. Stevenson, Humus Chemistry: Genesis, Composition, Reactions, Wiley Interscience, New York (1994). [2] G. R. Aiken, “Isolation and concentration technique for aquatic humic substances”, p. 363−385 in Humic Substances in Soil, Sediment and Water, G. R. Aiken, D. M. McKnight, R. L. Wershaw, P. MacCarthy, Edts., Wiley, New York (1985). [3] Y. Inbar, Y. Chen, Y. Hadar...

A Centro de Estudios Trandisciplinarios del Agua, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires. Av. Chorroarín 280 (C1427CWO), Ciudad de Buenos Aires, Argentina. B Centro de Formación e Investigación en Enseñanza de las Ciencias (CEFIEC), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II (C1428EGA) Ciudad de Buenos Aires, ...

Many studies tested different feed additives, among these additives, humic substances (HS) have been used in livestock and poultry diets. Humic substances commonly present in nature as they are created from the organic matter decomposition, and are normally found in the soil and natural water. Active components of HS consist of humic acid (HA), humus, ulmic acid, fulvic acid, humin and certain ...

Humic substances are generally seen as important soil and natural water components. They are formed during humification of organic matter by soil microorganisms. Humic substances are a mixture of complex organic compounds that are usually separated into three fractions: humic acids, fulvic acids and humins. The properties of humate products on the market depend on the ratios between these fract...

Results of extensive studies on the basic problems of extraction, isolation, fractionation and purification of soil humic substances are presented. Data on the degradation, functional group analysis and molecular weight determination of purified humic fractions froro the fJ -horizon of a podzol are reported, and the role of huroic substances in the podzolization process is discussed.