Answer: Phenylanine; Lysine
An amino acid mixture consisting of alanine, phenylalanine, and lysine is to be separated by normal phase HPLC. The stationary phase is polar and the mobile phase is a nonpolar solvent. The first amino acid to be eluted will be Phenylanine. The last amino acid to be eluted will be: Lysine
Explanation:
In normal phase HPLC (High performance liquid chromatography), the polar stationary phase would retain the less nonpolar amino acids (alanine and lysine) while the nonpolar mobile phase would permit the quick elution of the aromatic amino acid, phenylanine. Thus, phenylanine is first eluted.
This is then followed by the elution of the amino acid with nonpolar side chain, alanine. Thus, alanine is the second to be eluted.
Lastly, the positively charged amino acid, lysine will be released by the stationary phase. Thus, lysine is the last to be eluted
