Which statement about gradient elution is false?

Which statement about gradient elution is false?

• A. Gradient elution uses a mobile phase composition that changes during the run.
• B. Gradient elution often requires re-equilibration between runs.
• C. Gradient elution can improve separation of closely eluting compounds.
• D. Gradient elution eliminates the need to re-equilibrate the column after each run.

Answer: (D)