Pyrite as sensor for potentiometric precipitation titrations

Abstract

The potentiometric titration of chloride, bromide, iodide and thiocyanate with silver nitrate, using the mineral pyrite as a sensor for the detection of the end-point, is described. The potentials of the pyrite electrode were found to be established rapidly, and accurate and reproducible results were obtained. The pyrite electrode potential showed a sub-Nernstian dependence on the concentration of the ionic species investigated. In addition, lead(II) was determined by titration with potassium chromate and chloride by titration with standard mercury(I) solution. Accurate and reproducible results were also obtained in the reverse titrations.