Pharmaceutical Analysis

Chapter 2

Tri Keto Hydrindine Hydrate (Ninhydrin Reagent)

INTRODUCTION

Ninhydrin reagent is chemically known as tri keto hydrindine hydrate which gives positive reaction with α-amino acids, it produces violet colour due to the formation of amine of diketo hydrindylidene (or) diketo hydrin amine.

STRUCTURE

 

 

Triketo hydrindine hydrate

MECHANISM OF ACTION

• The initial step involves oxidative deamination of amino acids through a transitory iminoacid and α-ketoacid to CO₂, NH₃ and CHO containing one carbon atom less than the original amino acid and ninhydrin as reduced to hydrindantin which is in violet colour.

   

   

  Hydrindantin

   

• For stabilising ...