Study for the Methylaion Methods of Hydmxyaromatic Acids and Aromatic Polycarboxyic Acids as the Constituents of Humic Substances

Abstract

The methylation method with dazomethane is often used for the derivatization of the constituents of humic materials but it has some problems. We used three methylation methods, Diazomethane, Phase-Transfer-Catalyzed and Dimethyl Sulfate-Potassium Carbonate methylation to obtain reaction ratios for 22 kinds of aromatic model compounds. These compounds had hydroxy and carboxy substituents. The Dimethyl Sulfate-Potassium Carbonate methylation method was found to be best.
KMn04 degradation products of humic acid were also methylated by the three methods. As in the case of the model compounds, Dimethyl Sulfate-Potassium Carbonate methylation was found Best. The decomposition compounds in most cases were benzene polycarboxylic acids.