Pyrolysis-gas chromatography-mass spectrometry of soil humic acids. I. The low boiling point compounds

Abstract—Cryogenic Curie-point pyrolysis-gas chromatography-mass spectrometry has been applied to investigate the chemical composition of organic matter present in soils. Two soil fulvic acid fractions, a so-called soil polysaccharide fraction and polymaleic acid were analyzed. The soil polysaccharide fraction contains almost exclusively polysaccharides with major building blocks glucose, mannose and galactose. The soil fulvic acid fractions contain varying amounts of polysaccharides, lignins and lipids. Polymaleic acid structures were virtually absent in the podzol fulvic acid and absent in other soil organic matter fractions, indicating that these structures, previously suggested to be present in soil fulvic acids, do not play an important role