Selective extraction of the amorphous Al, Fe and Si oxides using an alkaline Tiron solution

Abstract

A selective chemical dissolution method has been worked out in order to characterize quantitatively amorphous Al, Fe and Si oxides simultaneously in soils. Based on theoretical considerations an alkaline Tiron solution was tried out. Experiments on well-characterized synthetic and natural substrates were carried out in order to find the optimum set of conditions of pH, temperature and reaction time. These are: an alkaline medium consisting of 0·1 m Tiron and buffered at pH 10·5, an extraction temperature of 80°C and an extraction time of 1 h.