Phthalein Purple

Phthalein Purple Metalphthalein; C₃₂H₃₂N₂O₁₂ +  aq (2411-89-4)

Indicator grade of commerce.

A creamy white to brown powder complying with the following test.

Sensitivity Dissolve 10  mg in 1  ml of 13.5m ammonia and dilute to 100  ml with water. To 5  ml of the solution add 95  ml of water, 4  ml of 13.5m ammonia , 50  ml of ethanol (96%) and 0.1  ml of 0.1m barium chloride VS ; the solution is bluish violet. Add 0.15  ml of 0.1m disodium edetate VS ; the solution becomes colourless.