Concept #1: Anion-Exchange Chromatography
Example #1: Circle the peptide below that elutes last during anion-exchange chromatography if the pH is ~7?
Practice: Which amino acid elutes last from an anion-exchange column at physiological pH?
Practice: Use the chart to determine which tripeptide would elute last from an anion-exchange column at pH = 9.3.
Practice: Which type of ion exchange chromatography would be best to separate a mixture of histidine and arginine?
His: pK1 = 1.8, pK2 = 9.3, pKR = 6.0 Arg: pK1 = 1.8, pK2 = 9.0, pKR = 12.5
Practice: Stationary resin compounds with carboxymethyl (CM) and diethylaminoethyl (DEAE) groups are shown below. Indicate which one is likely used in a cation exchange column and which one is likely used in an anion exchange column. Considering the following peptide at pH 7, should DEAE or CM groups be used as the stationary resin to purify the peptide?