A modified ninhydrin colorimetric analysis for amino acids
Abstract
A colorimetric method for the quantitative analysis of pure amino acids is described. It is a modification of one reported by Yemm and Cocking, which employs cyanide and ninhydrin. The present method avoids the necessity for the preparation of solutions of reduced ninhydrin, which is an unstable reagent difficult to prepare and impracticable to store.
The method is applicable to amino acid mixtures when allowances are made for slight variability of color yields, and the presence of interfering compounds.
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