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 0f 0.l 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 0-horizon was bound t0 these acids. In the lower horizons Al coincided with the UV-trace at 400 run 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