NINHYDRIN — triketogidrinden-hydrate (2,2-dihydroxy-1,3-indan-dion), C 9 H 6 O 4 ; it is applied in chemical, biochemical and clinicodiagnostic researches to detection and quantitative definition of alpha amino groups.
N apply to quantitative definition free Aminonum of imino-acids, to definition of amine nitrogen in urine and blood serum, and also to manifestation hromatogramm at chromatographic fractionation of mix of amino acids (see. Chromatography ).
Pier. the weight (weight) of N. is equal to 178,15; t ° pl anhydrous N. 239 — 240 °.
The N, being a strong oxidizer, causes the oxidizing deamination of amino acid leading to formation of ammonia, carbon dioxide, corresponding aldehyde and the got into condition N. (see. Deamination ), edges reacts many N. and ammonia. At the same time the connection painted in blue-violet color with a maximum of absorption at 570 nanometers is formed. Prevention of oxidation of the painted salt the dissolved oxygen requires presence of reducing agent, napr, stannous chloride. Imino-acids at reaction with N. give bright yellow coloring with a maximum of absorption at 440 nanometers. It allows to use N. for definition of imino-acids in the protein hydrolyzates containing excess of amino acids.
Sensitivity and reliability of ninhydrin test such is that 0,1 mkmolya amino acids gives coloring, intensity a cut is reproduced with an accuracy of several percent.
Bibliography: Biochemical methods of a research in clinic, under the editorship of A. A. Pokrovsky, M., 1969; JI A. Biokhimiya's enindzher, Molecular bases of structure and function of a cell, the lane with English, M., 1976; Rabinovich V. A. and Havin 3. Ya. Short chemical reference book, L., 1978; Modern methods in biochemistry, under the editorship of V. N. Orekhovich, t. 1, M., 1964.
H. N. Zolotov.