The Chromatography of Amino Acids on Ion Exchange Resins. Use of Volatile Acids for Elution

Abstract

For the isolation of pure amino acids from protein hydrolysates, it is advantageous to have available chromatographic systems in which the eluants can be removed by simple evaporation. The method previously outlined in preliminary form, wherein amino acids are eluted from a sulfonated polystyrene resin (Dowex 50-X8) with HC1, has proved useful for this purpose, but the resolving power has not been sufficient to permit isolation of all of the common constituents of protein hydrolysates. In the procedure described in the present communication, aspartic acid, glutamic acid and tyrosine are isolated by passage of the hydrolysate over a 30-cm. column of the acetate form of Dowex 1-X8 (a strongly basic resin) using 0.5 N acetic acid as eluant, and the remaining components of the mixture are separated on a 150-cm. column of Dowex 50-X4 by elution with 1 to 4 N HC1. © 1954, American Chemical Society. All rights reserved.