High pressure liquid chromatography reversed phase, selectivity

Reverse phase, C-18. This coating consists of 0.05 mm diameter porous glass beads with a layer of octadecylsilane bonded to the surface. The purpose of the coating is to duplicate as closely as possible the column conditions for high pressure liquid chromatography (HPLC) regarding the solvent selection. TLC is much faster than HPLC but is difficult to quantitate. These plates contain 19 rows of 1 cm x 20 cm. 

A unified theory recently proposed to explain the manner of sorption and the form of sorption isotherm in gas, liquid, and ion-exchange chromatography is presented in some detail. Selectivity in reversed-phase high-pressure liquid chromatography is explored at length. Several chapters deal with characterization of bonded phases, relationship of column-packing structure and performance, variability of reversed-phase packing materials, and the differences between silica-based reversed-phase and poly(styrene-divinylbenzene) columns. A short review is included to cover various approaches used in HPLC to achieve the desired selectivity for resolution of enantiomeric compounds. 

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