2,3,5-Triphenyltetrazolium Chloride

Tetrazolium salt; C₁₉H₁₅ClN₄ = 334.8 (298-96-4)

Analytical reagent grade of commerce containing not less than 98.0% of C₁₉H₁₅ClN₄.

A pale yellow or cream powder; melting point, about 240°, with decomposition.

Assay Dissolve 1 g in a mixture of 5 mL of dilute nitric acid and 45 mL of water, add 50 mL of 0.1m silver nitrate VS and heat to boiling. Allow to cool, add 3 mL of dibutyl phthalate, shake vigorously and titrate with 0.1m ammonium thiocyanate VS using 2 mL of ammonium iron(iii) sulfate solution R2 as indicator. Each mL of 0.1m silver nitrate VS is equivalent to 33.48 mg of C₁₉H₁₅ClN₄.

Store protected from light.