Gzil P, Vervoort N, Baron G V, Desmet G
Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, 1050 Brussels, Belgium.
Anal Chem. 2003 Nov 15;75(22):6244-50. doi: 10.1021/ac034345m.
A series of theoretical calculations is presented to quantify the gain in LC separation efficiency that can be expected if the traditionally used packed bed columns were replaced by columns with a perfectly ordered flow-through pore network. It is shown that a perfectly ordered 2-D array of porous cylindrical pillars could yield reduced plate heights as small as h = 0.65 (for k' ' = 0.75) to h = 0.85 (for k' ' = 2) and separation impedances as small as E = 200 (for k' ' = 0.75) to E = 300 (for k' ' = 2) without having to compromise on the porosity (epsilon = 0.4) and the retention capacity of the packed bed of spheres. Fitting the calculated van Deemter plots with Knox's equation especially shows a strong decrease of the A-term contribution, hence confirming that the improved column performance indeed stems from the increased homogeneity of the packing. The presented results, hence, provide a clear quantitative support for Knox's recent argumentation that the use of more uniform beds could greatly enhance the efficiency of pressure-driven LC.
本文提出了一系列理论计算，以量化如果将传统使用的填充床柱替换为具有完美有序流通孔网络的柱，预期在液相色谱分离效率方面的提升。结果表明，二维排列完美有序的多孔圆柱柱可以实现低至h = 0.65（对于k'' = 0.75）到h = 0.85（对于k'' = 2）的理论塔板高度降低，以及低至E = 200（对于k'' = 0.75）到E = 300（对于k'' = 2）的分离阻抗降低，且无需在孔隙率（ε = 0.4）和球形填充床的保留容量上做出妥协。用诺克斯方程拟合计算得到的范第姆特曲线尤其表明A项贡献显著降低，从而证实了柱性能的改善确实源于填充均匀性的提高。因此，本文结果为诺克斯最近的观点提供了明确的定量支持，即使用更均匀的床层可以大大提高压力驱动液相色谱的效率。
