Abstract
A highly sensitive method for the determination of trace amounts of Mn (II) is based on the catalytic effect of Mn (II) on the autoxidation of 3-ethyl-2-thiohydantoin (ETH). Under given conditions of concentrations of reactants, temperature and reaction time, the coloration due to the oxidation of ETH in alkaline solution is proportional to the concentration of Mn (II) present. Mn (II) is determined by measuring the absorbance of the colored sample solution at 500 nm. Concentrations in the range of 2 to 16 ng of Mn (II) may be determined. The present method was applied to the analysis of natural water.