The recent re-emergence of core-sell particles in HPLC has enjoyed great success. In its current form, this technology has been optimized for the analysis of both small molecular weight analytes and large bio-molecules. Commercial columns made with such particles, available now from all major suppliers, have been shown to provide higher levels of performance compared to traditional columns.
Currently, further improvements in UHPLC levels of performance are explored by particle miniaturization. In this presentation it is shown that while significant improvements are still possible, the options available for accomplishing them are severely limited by commercial UHPLC instrument operational capabilities. Even the shortest commonly used UHPLC columns made with 1.0-1.2 µm particles can generate back pressures and peak volumes that challenge the limits of currently available commercial UHPLC instruments. These instrumental limitations set the lower practical limit of core-shell particle size to ~1.3 µm, for now.
Significant improvements in UHPLC performance with 1.3 µm Kinetex core-shell particles will be shown, demonstrating the practical utility of this novel material. HETP values generated with model test compounds were as low as 2.3 µm. Such values have never been reported in the literature previously. Real-world separations will also be shown, demonstrating that Kinetex 1.3 µm can provide minimal peak widths and superior peak capacity values when analyzing complex samples such as protein digests. H/u curves generated on columns made with Kinetex 1.3 µm core-shell particles suggest that frictional heating is not limiting the performance of such columns either in terms of minimum HETP values or at maximum flow rates applicable to such columns. The data presented will show that Kinetex 1.3 µm columns provide the highest chromatographic efficiency among all commercially available UHPLC columns today.