Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic.
J Sep Sci. 2020 May;43(9-10):1628-1633. doi: 10.1002/jssc.201901331. Epub 2020 Feb 9.
Thirty years after their introduction, monolithic stationary phases are an important member of chromatographic phases. When compared to conventional particulate materials, the continuous internal structure of both inorganic silica and organic polymer monoliths allows some hydrodynamic and analytical possibilities that are not provided by conventional particulate stationary phases. Polymer-based monolithic stationary phases offer simple preparation and straightforward surface modification, which makes them very versatile materials that are applicable, for example, as chromatographic stationary phases, sample enrichment units, enzymatic reactors, and external trigger-responding materials. On the other hand, current polymer monoliths cannot compete with efficiency provided by superficially porous and sub 2 µm particles. In this highlight article, I take advantage of the 30th anniversary of their introduction to discuss several concerns related to polymer-based monolithic stationary phases. Particularly, I focus on preparation repeatability, porous properties, swelling of the polymers in organic solvents, column efficiency for small molecules, and heterogeneity of dominant flow-through pores. In the end, I offer three possible approaches on how to overcome drawbacks related to stationary phases heterogeneity to further increase the applicability of polymer-based monolithic stationary phases.
30 年前问世以来，整体式固定相已成为色谱固定相的重要成员。与传统的颗粒状材料相比，无机硅胶和有机聚合物整体式固定相的连续内部结构提供了一些常规颗粒状固定相所不具备的流体动力学和分析可能性。基于聚合物的整体式固定相具有简单的制备和直接的表面修饰特点，因此具有广泛的适用性，例如可用作色谱固定相、样品富集单元、酶反应器和外部触发响应材料。另一方面，目前的聚合物整体式固定相在效率方面无法与表面多孔和亚 2μm 颗粒相媲美。在本文中，我将利用它们问世 30 周年之际，讨论与基于聚合物的整体式固定相相关的几个关注点。特别地，我将重点关注制备重复性、多孔特性、聚合物在有机溶剂中的溶胀、小分子的柱效以及主导贯穿孔的非均质性。最后，我提出了三种可能的方法来克服与固定相非均质性相关的缺点，以进一步提高基于聚合物的整体式固定相的适用性。
