Turbidimetric determination of sulfate ion in the water-soluble matter collected by deposit gauge

Abstract

A rapid turbidimetric method for the determination of sulfate ion in the water-soluble matter collected by the deposit gauge is described. In order to form a stable barium sulfate suspension and to select an optimum wavelength, a new procedure was studied.
Ten ml of the filtrate from the insoluble solids determination is treated with 1 ml of 1N hydrochloric acid, 4 ml of glycerin-alcohol solution (1+2) and approximately 0.3g of barium chloride crystals, mixed well and allowed to stand for 20 min. The barium sulfate suspension obtained by this procedure is very suitable for the determination of absorbancy. The proposed method is applied for routine analysis of water-soluble matter containing less than 100 μg/ml of sulfate ion. The relative error in determination is ± 5% in 10 to 150 ppm range of sulfate ion and an analysis requires 30 min.