Characterization of humic and fulvic acids from Gorleben groundwater

Summary The humic material extracted from one of the Gorleben groundwaters is separated into humic and fulvic acids, and characterized, together with a commercial humic acid from Aldrich Co., for their chemical composition, size distribution, proton exchange capacity and spectroscopic characteristics. The results are compared with one another and with the literature data of other humic acids. The humic acid is fractionated by gel permeation chromatography into different size groups and the fractions are subjected to IR and ¹H-NMR spectroscopy. The high molecular weight fractions (>70000 Dalton) are poor in carboxylic groups, whereas the major fractions (approx. 10000 Dalton) contain organic acids of large molecular entities.