Chromatographic Separation and Identification of Amino Acids Many chromatographic systems to separate amino acids have been reported. The solvents for two-dimensiond paper chromatography developed by Dus, el al. [Dus, K., BARTSCH,R. G., AND KAMEN, M. D., J. Biol. Chem., 237, 3083 (1962)) are unique in that they separate different classes of amino acids into a group-pattern. Reported here are modifications of the method of Dus, et al., to positively.identify zones of ninhydrin-developed amino acids in one fourth the separation time. Materials used were Eastman Chromagram sheet (cellulose, No. 6064), 20 X 20 om First direction solvent: n-hutanol, methyl ethyl ketone, water, 28% ammonia (25: 15:7:3) Second direction solvent: m-butanol, acetic acid, water (4: 1:5); upper layer T. L., HOLLAND, D. O., AND NAYLER, Color develooine resaents. from Hardv. el al. (HARDY, J. H. c.;A&~. f?h&m.; 27,971 (1
