Silica and other materials as supports in liquid chromatography. Chromatographic tests and their importance for evaluating these supports. Part II

Reversed-phase chromatography is the method of choice for the analysis of b asic compounds. However, because of the problems encountered with these com pounds, "base deactivated" stationary phases have been developed. This review focuses on a major problem encountered by the chromatographer w hich is to effectively choose, for a particular separation, the appropriate reversed-phase packing. Often, columns of the same type but provided by various manufacturers vary in their chromatographic behaviour. It is known that differences in the pur ity of column packings, in the properties of silica gel supports and the de nsity of silanols on the surface can be responsible for chromatographic dif ferences. Unfortunately, in the case of "base deactivated" columns there is no univer sal test and chromatographic effects are compound dependent. The aim of thi s review is to describe the various chromatographic tests proposed in the l iterature for the differentiation of the many stationary phases on the mark et.