Amino acid analyzers are instruments that automatically separate amino acids by cation-ex...

Amino acid analyzers are instruments that automatically separate amino acids by cation-exchange chromatography. Predict the order of elution (first to last) for each of the following sets of amino acids at pH = 4.

(a) Gly, Asp, His

(b) Arg, Glu, Ala

(c) Phe, His, Glu