Pellicular stationary phases

Pellicular packings generally utilise a glass bead support and are usually of the size 30-50 jam. These supports suffer from a very low capacity (in the range of 5-50 jaEq/g). They also give low k values and require smaller sample sizes. 

---

With the recent growth of biopolymer HPLC, there has been a renewed interest in pellicular stationary phases for analytical applications. Unger and co-workers (19)... 

Conventionally, the phase ratio is the volume of the active moieties of the stationary phase divided by the volume of the mobile phase in the column. From the particular configuration of pellicular stationary phases described earlier, it follows that they have a relatively low phase ratio with respect to that of the conventional packing materials employed in HPLC. 

The elevated mechanical and thermal stabilities of pellicular stationary phases having a solid, fluid-impervious core have favored the development of nonporous particles tailored for the rapid HPLC analysis of peptides, proteins, and other biopolymers. Most of these applications are in RPC. 

Fig.l Schematic representation of pellicular stationary phases consisting of covalently bonded functional groups at the surface (a), functionalized layer-encapsulating solid particles (b), and functionalized latex particles electrostatically bound to a solid core bearing groups of opposite charge (c). 

Columns packed with pellicular stationary phases of small particle size have low permeability and, therefore, cannot be operated at relatively high flow rates due to the pressure limitation of commercial HPLC instruments. However, due to the non-porous structure, micropellicular particles are generally more stable at higher temperature than conventional porous materials. Consequently, in the... 

---