Characterization of sedimentary humic matter by alkaline hydrolysis

Abstract

Humic matter fractions from modern sediments of Lake Huron and Lake Michigan have been compared. Large yields of saccharinic acids from alkaline hydrolysis suggest that these fractions contain large portions of carbohydrate materials. Evidence for contributions of aquatic lipid (C-16 fatty acids) and of liginin (phenolic acids) to these sediments is also present in the hydrolysis products. Qualitative differences among fulvic acid, humic acid and humin from the same lake are minor, suggesting common (or similar) organic sources for these fractions. The lability of sedimentary humic matter to alkaline hydrolysis is inversely related to its degree of exposure to oxidative weathering. Lability may also be related to diagenetic state as fulvic acids generally yield greater quantities of hydrolysis components than humic acids which in turn yield more than humin.