Selenium in soil humic acid

Open Access
Publisher Website
Google Scholar
Abstract
The major part of soil selenium was recovered by repeated extractions with 0.1 M sodium hydroxide solution. The soil extract was fractionated into humic and fulvic acids, and the forms of selenium in the humic acid fraction were investigated. Since the major part of the inorganic Se added to the soil extract was recovered in the fulvic acid fraction, selenium in the humic acid fraction was considered to occur in organically-bound forms. Since Se is closely associated with the amino acids in the acid hydrolysate of humic acid, it is suggested that selenium may be present as seleno-amino acids which are the constituents of proteins or peptides contained in the humic acid fraction.