Many HILIC separations use a mass spectrometer for the detector, so volatile buffers like ammonium formate and ammonium acetate are very common. However, the high organic content of the mobile phase can cause buffer salts to precipitate, which can lead to downtime for instrument maintenance. In addition, high buffer concentrations can impact chromatography by reducing analyte retention. To avoid these effects, method optimization is required, and 10 mM is a good starting point for buffer concentration. Both the A and B mobile phases should be buffered equally in order to keep the ionic strength constant during a gradient for the most consistent MS detector response. Check with your MS vendor for the maximum buffer concentration they recommend for your ESI source.
Can I use buffers for HILIC separations? What kind and what concentration?
01 Aug 2025
Author
GNOT5088
