HILIC Retention Mechanisms

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Evidence suggests that the retention mechanism in HILIC is complex, and consists of a combination of:

  • Hydrophilic partitioning of the analyte between the aqueous-rich layer and the bulk of the mobile phase
  • Hydrogen bonding between polar functional groups and the stationary phase
  • Electrostatic interactions on ionized functional groups

Additionally, van der Waals interactions between the hydrophobic portions of the bonded ligands of the stationary phase and the non-polar part of the analytes may be present.