Mordant Black 11 Triturate

Mix 1 g of mordant black 11 with 99 g of sodium chloride.

Test for sensitivity Dissolve 50 mg in 100 mL of water. The solution is brownish-violet. On addition of 0.3 mL of dilute ammonia R1 the solution turns blue. On the subsequent addition of 0.1 mL of a 10 g/L solution of magnesium sulfate, it turns violet.

Store in an airtight container, protected from light.