Separation of organic low molecular weight aluminium complexes in soil solution by liquid chromatography

A size exclusion chromatography method was developed for the separation of Al complexes of low molecular weight organic acids in soil solution. Bio-Gel P2 was used in a 1.6 x 30 cm column and the mobile phase consisted of 0.1 M NaSCN of pH 4. The low molecular weight acids were determined 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 horizons Al coincided with the UV-trace at 400 nm indicating organic complexes. Si was found in one major peak which was assumed to be a low molecular weight compound possibly silicic acid. As a compliment ultrafiltration was employed for characterisation. Copyright (C) 1996 Elsevier Science Ltd