Technische Universität Darmstadt, Petersenstraße 22, 64287 Darmstadt, Germany; Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany.
J Chromatogr A. 2013 Nov 8;1315:127-34. doi: 10.1016/j.chroma.2013.09.059. Epub 2013 Sep 19.
It is well-known that the open tubular column design basically can offer very high plate numbers. Experimental realization has however not kept pace with theoretical considerations, lacking efficient methods for the deposition of a thick film porous layer within a microbore capillary. A previously published sol-gel synthesis method was extended from 20 μm to 10 μm inner diameter fused silica capillaries and the resulting columns were compared to a monolithic reference capillary in terms of kinetic performance at pressure maximum. Column permeability was investigated and pressure/flow-diagrams were obtained with a 400-fold permeability gain for the open tubes. Structural characterizations regarding layer thickness and surface porosity were carried out and displayed via scanning electron microscopy and nitrogen sorption analysis. Chromatographic results in normal phase mode at elevated mobile phase flow rate reveal the intrinsic performance potential of this column format when it comes to kinetic performance limitation plots, which were constructed for all columns prepared and compared to the monolithic silica reference capillary.
众所周知，开管柱设计基本上可以提供非常高的理论塔板数。然而，实验实现并没有跟上理论考虑的步伐，缺乏在微径毛细管内沉积厚多孔层的有效方法。先前发表的溶胶-凝胶合成方法从 20μm 内径扩展到 10μm 内径熔硅毛细管，所得柱在压力最大时的动力学性能方面与整体柱参考毛细管进行了比较。研究了柱渗透性，并获得了开管的渗透性提高了 400 倍的压力/流量图。通过扫描电子显微镜和氮气吸附分析进行了结构特性分析，并进行了显示。在升高的流动相流速下的正相模式下的色谱结果揭示了这种柱格式在动力学性能限制图方面的固有性能潜力，这些限制图是为所有制备的柱构建的，并与整体硅参考毛细管进行了比较。
