Chapter 22.5, Problem 18P

Interpretation Introduction

Interpretation:

The elution order of given amino acids with $\text{pH-4}$ buffer through a column packed Dowex-1 should be given.

Concept introduction:

Ion-exchange chromatography is used to separate mixture of amino acids on the basis of their overall charge by using cation or anion-exchange resins.

Dowex-1 is an anion-exchange resins with less polar used for anion-exchange chromatography.

Anion-exchange chromatography separate amino acids according to their $pI$ values, the lesser the $pI$-value of an amino acid as compared to given pH have the high concentration of negative charged ions. The negative charged ions elute (release from chromatogram) slowly from the anion-exchange chromatogram and the positive charged ions elute easily from the anion-exchange chromatogram.