Alkaline Permanganate Oxidation of Methylated and Unmethylated Fulvic Acid

Abstract

AbstractThe alkaline permanganate oxidation of humic and fulvic acids yields small amounts of benzene polycarboxylic acids that range from the di‐ to the hexa‐form. Low yields may be due to the presence of electron‐donating substituents, such as OH groups, on aromatic rings. To make the rings less susceptible to destruction by alkaline KMnO4, we attempted to reduce the electron‐donating effect by converting OH groups via methylation to OCH3 groups. The alkaline permanganate oxidation of methylated FA, however, yielded the same types and similar amounts of benzene carboxylic acids as that of the untreated FA. Failure of methylation to increase the variety and yield of oxidation products may be due to inability to either methylate all (phenolic) OH groups or, more likely, to reduce electron‐donating effects sufficiently.