A simple gravimetric method for the determination of perchlorate

A simple, inexpensive, and accurate gravimetric procedure for the determination of the perchlorate ion (ClO4 (-)) is described. The method is based on the precipitation of potassium perchlorate, KClO4(s), from wet ethanol solution using potassium acetate in ethanol as the precipitant. The method is particularly suited to the analysis of the concentrated perchlorate solutions commonly used in physicochemical, electrochemical, and solubility studies. An accuracy of 0.1-0.2% was readily attainable providing the water content of the precipitating medium was <= 5 vol%. Solubility data for KClO4(s) in ethanol-rich mixtures with water are reported.