SEPARATION OF ORGANIC LOW-MOLECULAR-WEIGHT ALUMINUM COMPLEXES IN SOILSOLUTION BY LIQUID-CHROMATOGRAPHY

A size exclusion chromatography method was developed for the separatio n of Al complexes of low molecular weight organic acids in soil soluti on. Bio-Gel P2 was used in a 1.6 x 30 cm column and the mobile phase c onsisted of 0.1 M NaSCN of pH 4. The low molecular weight acids were d etermined by HPLC. The results show that 28-37% of the Al in the soil solution of the O-horizon was bound to these acids. In the lower horiz ons Al coincided with the UV-trace at 400 nm indicating organic comple xes. Si was found in one major peak which was assumed to be a low mole cular weight compound possibly silicic acid. As a compliment ultrafilt ration was employed for characterisation. Copyright (C) 1996 Elsevier Science Ltd