PYROLYSIS METHYLATION - A METHOD FOR STRUCTURAL ELUCIDATION OF THE CHEMICAL NATURE OF AQUATIC HUMIC SUBSTANCES/

Pyrolysis has been used for the last ten years to study the chemical n ature of humic substances. However, obtaining data is hampered by anal ytical limitations. One of these is that carboxylic acids other than f atty acids are not usually present amongst pyrolysis products. To over come this problem, a novel method - pyrolysis/methylation - is applied . Simultaneous pyrolysis/derivatization with tetramethylammonium hydro xide protects the carboxyl groups by formation of methyl esters. At th e same time, partial methylation of hydroxyl groups occurs. This metho d permits the identification of a suite of carboxyl-containing aromati c and aliphatic compounds, not previously observed in conventional pyr olysis, providing useful information on the biodegradation processes o f plant materials leading to macromolecular humic substances.