Quantitative chromatographic methods. 5. An improved ninhydrin-hydrindantin reagent.

Abstract

An improved ninhydrin–hydrindantin reagent has been developed for the quantitative determination of amino acids and peptides separated on filter paper chromatograms. This represents a modification of a reagent described earlier, which was based in turn upon the well-known solution of Moore and Stein. The present reagent has been in use for several years and has shown the advantages of high stability, extremely low and steady reagent blank values, and approximately stoichiometric yields of Ruhemann's purple for most amino acids. In addition to its use for determinations on excised areas from filter paper chromatograms, conditions are defined for the use of the reagent for determinations of amino acids in solutions.