Abstract
Cation exchange and size exclusion high-performance liquid-chromatographic methods with postcolumn fluorescence detection using 5-sulfo-8-quinolinol were applied to the chemical speciation of aluminum in soil-extract samples. The addition of an appropriate amount of F- to the postcolumn reagent solution makes it possible to eliminate the interference of F- in a sample with Al3+ detection. The reliability of this method was evaluated by a computer-assisted equilibrium calculation for aluminum species and ICP atomic emission spectrometry. Considerable parts of water-soluble Al3+ (the Al3+ fraction extracted into distilled water) in both sedimentary and granitoid soil samples were found to be complexed with organic substances. On the other hand, exchangeable Al3+ (the Al3+ fraction extracted into 1mol dm-3 KCl) in granitoid soil samples was mostly free Al3+
