Determination of the stoicheiometry of complexes by flow procedures. Molar-ratio and Asmus methods

Abstract

Molar-ratio and Asmus methods for the determination of the stoicheiometry of complexes were adapted to flow techniques. The procedures were tested for La^III-Arsenazo I, Fe^II-1,10-phenanthroline, Th^IV-Thorin, Th^IV-Alizarin S and Ce^III-Arsenazo III. The method proposed is based on the merging of two solutions (metal and reagent), keeping the flow-rate of one of them constant and increasing the other stepwise. The graphs obtained and their theoretical basis are discussed.