COEI-2-SULFAT Search for sulphates

In a 160  16 mm test tube, place the volume prescribed of the solution obtained by the means indicated in each monography; add 1 ml of diluted hydrochloric acid (R); adjust to 20 ml with water and add 2 ml of barium chloride solution at 10% (R).

Compare the opalescence or any cloudiness to the control sample prepared with 1 ml of solution at 0.100 g of sulphuric acid per litre (i.e. 0.10 mg of H2SO4,) with 1 ml of diluted hydrochloric acid (R) and water until volume of 20 ml and 2 ml of barium chloride solution (R). This tube contains 100 μg of H2SO4.