Humic substances in Baltic Sea sediments

Abstract

Humic substances in sediment samples from sorne of the oxic and anoxie basins in the Bal tic Sea were studied.The humic material constituted 30-55% of the organic matter and had a higher content of fulvie acids than humic acids.The >300000 molecular weight fraction was found to constitute the major portion of the humic acids, whereas the fulvie acids were mainly composed of two mol.wt groups> 300 000 and < 10 000.Data on the elemental analysis, functional groups and IR absorption characteristics suggest that the hurnic material is formed from a similar type of organic matter in the Gulf of Bothnia, the Baltic Proper and the Gulf of Finland, and is of mixed origin (autochthonous and allochthonous).This may be a characteristic of partially or semi-enclosed basins.