Tetralone blue test

The ether extract and the water layer may be tested for the presence of /3-tetralone or the bisulfite addition product by the tetralone blue test. 

Tetralone blue test. A few drops of the organic solvent layer or the aqueous phase is shaken in a test tube with 2 ml. of 95% ethanol, and 10 drops of 25% sodium hydroxide solution is poured down the side of the tube. In the presence of air a deep blue color appears at the interface within 1 minute. 

---