Spectrophotometric Method for the Determination of Small Amounts of Sulfate Ions

Abstract

The authors have devised a new method for the determination of small amounts of sulfate. Sulfate is precipitated as barium sulfate using barium chromate suspension in an acid solution (0.5 M acetic, 0.01 M hydrochloric acid), and the excess of barium is almost completely precipitated as barium chromate by adding ammonia water (containing calcium ion) and ethanol. Finally the amount of chromate which is exchanged with sulfate is estimated.The proposed method may be applicable to the determination of 0.3–100p. p.m. sulfate with satisfactory results.