Matthew Przybyciel

Unlike reversed-phase liquid chromatography, SFC lacks a universal stationary phase. Thus, it is important to re-evaluate the default column screening library used with SFC. In this study, three uncommon achiral SFC columns were investigated and compared to three popular stationary phases.

The author describes several commercially available novel phases for high performance liquid chromatography separations. Novel phases can provide an alternative and complementary separation for many analyses performed on C8 or C18 columns. Many of the separations discussed in the article could not be accomplished on C8, C18, or even phenyl phases.

Guest columnist Matt Przybyciel reviews the structure, behaviour and applications of both alkyl- and phenyl-fluorinated phases in HPLC. The author presents some guidelines on potential areas of application for alkyl and phenyl-fluorinated phases, in which conventional C8, C18 and phenyl phases might have insufficient selectivity or too strong retention.

Guest columnist Matt Przybyciel reviews the structure, behavior, and applications of both alkyl- and phenyl-fluorinated phases in HPLC.

Reversed-phase high performance liquid chromatography (HPLC) is one of the most utilized forms of chromatography (1). The C8 and C18 stationary phases are the most widely used for reversed-phase HPLC. However, analysts occasionally encounter difficult separations for which selectivity, ruggedness, or reproducibility are not obtained easily using traditional C8 and C18 phases. These separations might require the use of novel or selective phases that interact with analytes in a manner different than C8 or C18 phases (2). These types of stationary phases separate compounds based upon selective stationary phase interactions such as steric recognition charge transfer or ?–? interactions (3). One class of selective or novel phases that have been used for a variety of separations are fluorinated phases (4). These fluorinated phases have provided an alternative and complementary separation for many analytes performed on C8 or C18 columns. Fluorinated phases can provide different elution orders, leading to..

Continued from last month, this month's column discusses specially designed columns for use in highly aqueous environments. Many of these columns also can be used as regular reversed-phase columns for a range of mobile phases.

The authors suggest ways to avoid phase collapse and regenerate collapsed phases.