In Reverse Phase chromatography of a mixture of protein and sodium chloride:
In Reverse Phase chromatography of a mixture of protein and sodium chloride:
Select an option to attempt
Correct Answer: Option A
Explanation
Elution order in Reverse Phase chromatography:In Reverse Phase chromatography (RP-HPLC), the stationary phase is nonpolar (e.g., C18 alkyl chains), and the mobile phase is polar (aqueous/organic).Elution order is governed by hydrophobicity:• Polar/ionic molecules (low hydrophobicity) → elute FIRST (do not interact with stationary phase)• Nonpolar/hydrophobic molecules → elute LATER (retained by stationary phase)For a protein + NaCl mixture:• NaCl is ionic and highly polar → barely retained → elutes FIRST• Protein (especially if it has hydrophobic patches) → retained on C18 → elutes LATERAnswer: Salt will elute before the protein (Option 1).