The Characteristic Lignin Signature of Aquatic Humic Substances

Dissolved Organic Carbon (DOC), a dynamic facet of water chemistry, can be divided into many different groups. One of these groups, the aquatic humics substances, contains an important compound called lignin. Lignin is a polyphenolic compound of various branching side chains particular only to vascular plants. The structure of the lignin is dependent on the plant family from which it comes. The macromolecule can be oxidized into distinct phenols that offer a wealth of information about the vegetation surrounding the sample site. Anthropogenic sources of lignin from paper and pulp mill waste water discharge may change his natural lignin signature. Cupric Oxide (CuO) is used to oxidize the lignin contained in the sample and the relative amounts and ratios of the different phenols are used to examine the waste water effects on the aquatic ecosystem.