POTENTIOMETRIC DETERMINATION OF SULFATE IONS USING A FLUORIDE-SELECTIVE ELECTRODE.

This paper examines the possibility of using fluoride-selective electrodes to determine sulfate ions in coking plant media. The authors developed a method of determining sulfate ions using a fluoride-selective electrode, based on precipitation of sulfates by barium ions, followed by potentiometric titration of the excess precipitation agent with a sodium fluoride solution. The method is intended for determination of sulfate ions in the working liquors of sulfur removal units, thiocyanate units, and the sulfate section, in waste water and other coking plant media. The advantages of the proposed method are: the possibility of determining sulfates in colored samples, the objective evaluation of the equivalence point, and the broad interval of determined sulfate ion concentrations. The relative error of the method is about 3%, the analysis time about 30 minutes.