THE SPECTROPHOTOMETRIC DETERMINATION OF AMINE, AMINO ACID AND PEPTIDE WITH 2, 4, 6-TRINITROBENZENE 1-SULFONIC ACID

Abstract

1. Primary amine, amino acid, and peptide at a concentration of 0.01 to 0.8μ mols per ml., could be assayed spec trophotometrically by the TNP-lation with TNBS.
2. Under the conditions described, the optical densities of various amino compounds were practically the same as those of the equivalent amount of the corresponding TNP-derivatives, which were 1.27×10⁴ for amino groups of amines and amino acids and 1.05×10⁴ for those of peptides at a final concentration of N, respectively.
3. TNP-lated sample, after the assay, could be recovered from the Spec tropho tome tric mixture and be used for the structural analysis.
We are indebted to Mrs. S. Sasakawa for the information on her unpublished data and to Mr. J. Nitta for the preparation of TNBS. This work was supported in part by the grant of Scientific Research Found of the Ministry of Education for which the authors wish to thank.