PolyEncap stationary phases are a family of bonded phases where the silica is polymeric encapsulated by acrylic acid ester polymers that are additionally covalent bonded to the silica surface. This type of stationary phases offers different selectivities compared to classical bonded brush type stationary phases. The PolyEncap phases show a slightly higher pH stability in basic mobile phases. Three different bonding chemistries are offered: These are two RP packings with C4 and C18 and one weak cation exchanger (WCX). The C4 also called PolyEncap A has a comparable selectivity to a brush type C8 packing, whereas the corresponding C18 (PolyEncap B) is similar to a brush type C18 packing. The WCX packing is able to separate mono valent and bivalent cations in a single run. The two RP bondings are available in four particle sizes (3 µm, 5 µm, 7 µm and 10 µm) and two pore sizes (120 Å and 300 Å) whereas the WCX packing is based on a 5 µm, 120 Å silica.