Chromatography Forum

Adding ACN can reduce the hydrophobic interaction in IEX. What's the mechanism? ACN interacts with the hydrophobic chain?

In typical RP-HPLC, ACN is used as mobile phase. Analytes interacts with the Carbon chain of the stationary phase. I never think about the ACN-reducing-the-hydrophobic-interaction story.

Is it contradictory?

Thanks

The ACN is in competition with the hydrophobic analyte, in other words, the more ACN, the more the equilibrium of the analyte is shifted toward the mobile phase.