Structure and performance of silica-based monolithic HPLC columns.
Structure and performance of silica-based monolithic HPLC columns.
复制标题
硅胶整体式 HPLC 柱的结构和性能。
DOI：
10.1002/jssc.200800213
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发表时间：
2008
影响因子：
3.1
通讯作者：
K. Cabrera
中科院分区：
文献类型：
--
作者：
S. Altmaier;K. Cabrera
以四甲氧基硅烷（TMOS）和聚氧化乙烯（PEO）为反应物，采用溶胶-凝胶相分离法制备了硅胶整体柱。所得整料显示出大孔和二氧化硅骨架直径以及相应的域尺寸（大孔和骨架直径的总和）的差异。所有的整料都合成为直径为4.6 mm，并以标准化和优化的方式用合适的聚芳醚醚酮（PEEK）聚合物包覆，用于所得整料HPLC柱的后续色谱评价。在正相条件下，使用正庚烷/二氧六环（95：5 v/v）作为移动的相，2-硝基苯甲醚作为供试化合物，对色谱柱进行检测，以测定分离效率和渗透性。制备了两组不同的柱：第一组中PEO的量逐步降低，以产生具有相同大孔体积和域尺寸变化的整料。合成第二组材料，调节TMOS和PEO的量以产生具有约1.80 μ m的相同大孔直径但不同骨架直径和大孔体积的整体柱。色谱结果表明，柱性能的提高不能通过任意减小给定柱的域尺寸来实现。从“缩小尺寸”的某个点，可以观察到整体结构的结构均匀性损失，这显然是色谱性能较低的原因。
Silica-based monolithic columns were prepared for HPLC with systematic variations of the tetramethoxysilane (TMOS) and polyethylene oxide (PEO) content as reactants in a sol-gel process accompanied by phase separation. The resulting monoliths showed differences in the macropore and silica skeleton diameter as well as in the corresponding domain sizes (the sum of macropore and skeleton diameter). All monoliths were synthesized with a diameter of 4.6 mm and cladded with a suitable polyaryletheretherketone (PEEK) polymer in a standardized and optimized manner for the subsequent chromatographic evaluation of the resulting monolithic HPLC columns. The columns were tested under normal phase conditions using n-heptane/dioxane (95:5 v/v) as a mobile phase and 2-nitroanisole as a test compound for the determination of separation efficiency and permeability. Two different sets of columns were prepared: the first one in which the amount of PEO was stepwise decreased to yield monoliths with identical macropore volumes and variations in the domain sizes. The second group of materials was synthesized adjusting both TMOS and PEO quantities to yield monolithic columns with identical macropore diameters of about 1.80 microm but different skeleton diameters and macropore volumes. The chromatographic results suggest that an increase in the column performance cannot be achieved by just arbitrarily decreasing the domain size of a given column. From a certain point of "downsizing" the monolithic structure a loss of structural homogeneity can be observed, which is apparently responsible for a lower chromatographic performance.