which of the following stains are suitable for detecting amino acids on a silica plates and give reason for the answer?
2 Aniline phthalate
3 Charring with 30% sulphuric acid
4 Pauly stain
5 Dragendorf reagent
Ninhydrin reaction, color reaction to a-amino acids, which is carried out byheating the latter in excess of an alkaline solution of ninhydrin and forms compounds that are violet-blue color. Proline and hydroxyproline, which do not have a-amino groups in the reaction with ninhydrin derivative form yellow. Ninhydrin reaction is not specific, since the colored product with ninhydrin give as NH3, etc. Comm. Containing amino group (including proteins and peptides). However, reactions to these Comm. performed without CO2 emissions, and ninhydrin reaction with CO2 is specific for a-amino acids.