CHARACTERIZATION OF HUMIC SUBSTANCES EXTRACTED FROM CANADIAN LAKE-SEDIMENTS

Humic substances (HS) were extracted from the sediments of four Sudbur y area lakes, namely, Tilton, Clearwater, Silver, and Ramsey Lakes, wi th the aid of 0.1 M Na4P2O7 and 0.5 M NaOH solutions. The HS (humic an d fulvic acids) were purified and characterized using the methods of e lemental analysis, visible spectroscopy (E-4/E-6 ratio), FTIR, and sol id-state C-13 CPMAS NMR. A substantial amount of information with rega rd to the composition and chemical nature of lake sediment HS was obta ined. The results obtained for the Sudbury area lake sediments were co mpared with one another and with HS from other sources, such as soils. The elemental composition, atomic ratios, E-4/E-6 ratios, and FTIR an d NMR features of the samples from the above lakes were found to be ne arly identical, suggesting that HS formed in the Sudbury area have sim ilar chemical properties. Compared with soil HS, the Sudbury lake sedi ments HS have undergone a low degree of aromatic condensation and are considerably more aliphatic in nature.