Determination of Sulphur in Solid and Liquid Samples by Potentiometric Titration with Ion Selective Electrode.

Abstract

Abstract This paper describes a potentiometric method for the determination of sulphur in solid and liquid samples, using a sulphide ion selective electrode after the reduction distillation step. The determination of sulphide in solid and liquid samples without prior treatment was carried out by direct and titration potentiometric methods. The reproducibility of the method and the recovery of sulphate in solid samples was investigated using analytical reagent grade 99% sodium sulphate. Portions of aproximately 100 mg of reagent were subjected to the reduction distillation process. After the ion selective electrode showed a stable value of the potential, indicating that all the sulphate had been reduced to sulphide, the potentiometric titration with lead nitrate solution was performed. A mean recovery of 98% of sulphate was found. The potentiometric titration method described in this work, can be applied to determine S= in solid samples with the advantage that it does not require sample solubilization or e...