Thermofractography of humic substances

Abstract

Thermofractography (TF) has been applied to humic and fulvic acids from four different soil types. Among the thermal products, 3,5-dihydroxybenzoic acid, catechol, 5-hydroxymethylfurfural, vanillin, phenol, furfural, guaiacol and indole were identified. These are typical fragments from lignins, microbial polyphenols, polysaccharides and proteins. Thermofractography appears to be an effective method for study of humic molecule structures by thermal degradation. Furthermore, it seems promising to differentiate humic acids from distinct soil types and to distinguish between humic and fulvic fractions.