Abstract
The methylation of humic acids has been studied on the view point of the determination of the acidic groups of humic acids, but the mechanisms of various methods of methylation have hardly been studied up to the present.We repeated the methylations of humic acids by various methods until the methoxyl contents of the reaction products reacted the constant value in each case, and carried out, at the same time, many other tests on the sample.From the results obtained from these experiments we determined the sorts and contents of the active groups of humic acids which were reacted by each methylation, and deduced the chemical structure of humic acids from this conclusion and other results which had been obtained previously.
