Organic acids can form stable complexes with metals and therefore can affect metal solubility and speciation. The low-molecular-weight aliphatic organic acids extracted in water and present in soil solution from O, A, Bh and Bt horizons from a group of forested Utlisols, Entisols and Spodosols were identified by high performance liquid chromatography (HPLC). Oxalic acid was found in all samples and was present generally in the highest concentrations. Oxalate concentrations in soil solution ranged from 25 to 1000 microM and were greater in the Bh and Bt horizon soils than in the A horizon soil. High concentrations of formic acid were also identified in most soils, ranging from 5 to 174 microM in soil solution. Trace amounts of citric, [...]
