Ninhydrin can be used as a chromogenic analytical probe for the quantification of amino acids and proteins.
Ninhydrin is used in amino acid analysis of proteins. Except proline, Most amino acids can be hydrolyzed and react with ninhydrin. The amino acids are then quantified colorimetrically after separation by chromatography.Ninhydrin reacts with primary and secondary amines producing a blue or purple reaction product: diketohydrindylidene-diketohydrindamine.
[1]. Omar MA, et al. Utility of ninhydrin reagent for spectrofluorimetric determination of heptaminol in human plasma.Luminescence. 2018 Sep;33(6):1107-1112. [2]. Anantharaman S, et al. Ninhydrin-sodium molybdate chromogenic analytical probe for the assay of amino acids and proteins.rSpectrochim Acta A Mol Biomol Spectrosc. 2017 Feb 15;173:897-903.