Hydrophilic interaction chromatography (HILIC) is a popular technique to analyze very polar molecules. However, it is often difficult to develop a robust method.

HILIC Columns: Disadvantages
・　Extremely sensitive to sample solvent used resulting in shifting retention time.
・　Small sample loading capacity – polar molecules do not dissolve well in organic solvents.
・　Peak distortion occurs if sample solvents are different than the mobile phase.

PBr Columns: Advantages
・　Retain very polar compounds in reversed-phase.
・　Use simple mobile phase, e.g. 100% aqueous or organic mobile phase.
・　Higher sample loading capacity than HILIC.
・　Robust
COSMOCORE (Core-shell based)
http://www.nacalaiusa.com/products/view/280/cosmocore-2-6pbr
COSMOSIL (Fully porus silica gel based)
http://www.nacalaiusa.com/products/view/238/cosmosil-5pbr