Mixed Reversed Phase/Beta Cyclo-Dextrin Packings in High Performance Liquid Chromatography: Single Mixed Support Column Versus Two Columns in Series

Abstract

A study of mixed C₁₈/β packings in high performance liquid chromatography was undertaken to evaluate the utility of such phases. The results show that non additive retention times are obtained when a mixed phase column is used while the retention times are additive when two columns, one packed with C₁₈ and the other with β are coupled in a series. A plot of corrected retention times vs % β in C₁₈ gave a non-linear result. This means that the prediction of retention times on a mixed phase column may not be easily done. As a result, in this case, it will be easier to couple two different columns of different selectivities to achieve a difficult separation.