Schiffs reagent

Method 1: Dissolve 0.2gm. of pure p rosaniline hydrochloride in 20ml. of a cold, freshly prepared, saturated aqueous solution of sulphur dioxide; allow the solution to stand for a few hours until it becomes colourless or pale yellow. Dilute the solution to 200ml. and keep it in a tightly stoppered bottle.The solution keeps well, and should not be exposed to light or air. Store in the dark.
Method 2: Add 2gm. of sodium bisulphite to a solution of 0.2gm.of p- rosaniline hydrochloride and 2ml.of concentrated hydrochloric acid in 200ml. of water.