Bromophenol Blue Solution

Bromophenol Blue Solution Dissolve 0.1  g of bromophenol blue in 1.5  ml of 0.1m sodium hydroxide and 20  ml of ethanol (96%) and add sufficient water to produce 100  ml (pH range, 2.8 to 4.6).

Complies with the following test.

Sensitivity A mixture of 0.05  ml of the solution and 20  ml of carbon dioxide-free water to which 0.05  ml of 0.1m hydrochloric acid VS has been added is yellow. Not more than 0.1  ml of 0.1m sodium hydroxide VS is required to change the colour to bluish violet.