The most versatile columns for this type of separation are some of the Cogent TYPE-C Silica™ columns because the amount of retention in both Reversed Phase and Aqueous Normal Phase ANP modes can be adjusted by adjusting the mobile phase composition.  

With Cogent TYPE-C Silica™ columns such as the Cogent Diamond Hydride™, we have observed not just Reversed Phase  and ANP mechanisms operating, but also some hydrophobic compounds retained by the ANP mechanism. 

In this latter case, certain functional groups such as amines or carboxylic acids are thought to play a significant role in ANP retention even if the compound is very hydrophobic.

Click HERE for Cogent Diamond Hydride™ ordering information.