Determination of Manganese by Flow Injection Analysis Based on Its Catalytic Effect on the Oxidative Coupling Reaction of 3-Methyl-2-benzothiazolinone Hydrazone with N,N-Dimethylaniline

Abstract

A catalytic-photometric method with a continuous-flow system was developed for the determination of nanogram amounts of manganese. The method is based on its catalytic effect on the oxidative coupling reaction of 3-methyl-2-benzothiazolinone hydrazone with N,N-dimethylaniline to form a blue-violet compound (λmax=590 nm) in the presence of hydrogen peroxide. In this reaction, 1,10-phenanthroline and citrate acted as activators for the catalytic action of manganese(II). Manganese(II) at the 2-30 ng ml−1 level can be determined at a rate of 10 samples h−1. The method can be applied to the determination of manganese in biological materials.