An evaluation of some oxidative degradation methods of humic substances applied to carbohydrate‐derived humic‐like polymers

SUMMARY Artificial polymers prepared by acid‐catalysed dehydration of glucose were examined by 13 C nuclear magnetic resonance (NMR), and subjected to degradation procedures frequently used in the study of humic substances: acid hydrolysis, persulphate degradation, alkaline permanganate oxidation, perborate depolymerization and cupric oxide oxidation. The ethyl acetate–soluble degradation products were identified by combined gas chromatography‐mass spectrometry. The compounds released in the perborate and in the cupric oxide treatments are as would be expected from a polymer derived from glucose dehydration products. Such degradation patterns contrasted with those obtained by alkaline permanganate oxidation, which resembled those of humic‐ or lignin‐like substances.