Palintest AP154 Sulfate Reagent Tablets 250 per box. The Palintest Sulfate test is based on a single tablet reagent containing barium chloride in a slightly acidic formulation. Barium salts react with sulfates to form insoluble barium sulfate. At the sulfate levels encountered in the test, this is observed as turbidity in the test sample. The degree of turbidity is proportional to the sulfate concentration and is measured using a Palintest Photometer.