Aromatic constituents of humic acids released by na-amalgam reductive cleavage, koh fusion and zinc dust fusion

Abstract

Abstract Eight humic acids showing different degree of humification were treated with HCI (1:1). The hydrolyzed humic acids were subjected to reductive cleavage with Na-amalgam, KOH fusion and zinc dust fusion. The yields of degradation products were determined by colorimetry gas chromatography. The perimental results Were summarized as follows: l. The amounts of ether-soluble substances obtained by reductive cleavage with Naamlagan ranged from 21.6% for Kuragari (A type) to 7.8% for Kisokoma B2 (Rp type). The yields of phenolic substances expressed in terms of vanillic acid content ranged from 3.0% for Kuragari (A type) to 1.8% for Kisokoma B2 (Rp type). Resorcinol. p.hydroxybenzoic acid, vanillic acid, protocatechuic acid and syringic acid were detected in the gas chromatograms of the ethe-soluble substances and their total yield comprised less than 0.6% of the Kisokoma F (Rp type). 2. The KOH fusion of humic acid yielded a larger amount of degradation products as compared to reductive cleavage. The amo...