Sodium Bisulfite Addition Complex



Aldehyde and Ketone

Sodium bisulfite addition complex for aldehydes and ketones.


Procedure

Place 1 mL of sodium bisulfite reagent in a test tube and add 0.3 mL or 300 mg of unknown. Stopper the test tube and shake vigorously.

Sodium bisulfite reagent: Add 1 mL of ethanol to 4 mL of a 40% aqueous solution of sodium bisulfite. Decant or filter the solution prior to use.

Positive Test

Formation of a precipitate is a positive test.

Complications

Aryl methyl ketones form the precipitate slowly or not at all.

Addition complex stable only in neutral solution.