Using a cation exchange resin, a mixture of four amino acids,
Asp (pKa 3.9), Arg (pKa 12.5), Ser (pKa 13) and Lys(pKa 10.5) are
separated using an elution gradient of increasing NaCl solution.
What would be the correct elution sequence? Explain your reasoning.
Draw the chromatogram would look like for this mixture if there was
twice as much Asp and Arg in the sample than Ser and Lys.