Chromatographic properties of reversed phase stationary phases under pressure and electro driven conditions. Effect of buffer composition

Four different reversed-phase (RP) stationary phases (CEC Hypersil C18, Zorbax Rx SIL C18, Zorbax 300 Rx SIL C18 and Zorbax PSM1000/C18) were examined under high-performance liquid chromatographic (pressure-driven, HPLC), and capillary electrochromatographic (electro-driven, CEC) conditions using an acetonitrile mobile phase combined with twenty different buffer systems (different cations, anions, pH and/or ionic strengths). Chromatographic performance tests under HPLC and CEC conditions were carried out using acidic, basic and neutral polar/non-polar compounds. Parameters such as plate number, retention factor and asymmetry were used to describe the behavior of the RP-columns under both HPLC and CEC conditions. The buffer systems differently influence chromatographic characteristics of porous RP-phases under CEC and HPLC conditions. Thus the choice of an appropriate buffer can be critical for an application applied on an entire system.