Measurement of exchangeable aluminium in soils and clay minerals by isotopic exchange

Abstract

Isotopically exchangeable Al was determined in soils and clay minerals by equilibration with ²⁸Al. Best results were obtained with a weak extractant and an equilibration time of eight min. The calculated amount of isotopically exchangeable Al was independent of the amount of carrier-Al added with the ²⁸Al. In some soils isotopically exchangeable Al did not appear to be related to the amount of Al which could be extracted by various electrolyte solutions. This technique provides an improved means of studying the exchange reactions of Al in acid soils and clay minerals.