Lan K, Jorgenson J W
Department of Chemistry, University of North Carolina at Chapel Hill 27599-3290, USA.
Anal Chem. 1998 Jul 15;70(14):2773-82. doi: 10.1021/ac971226w.
The progressions of peak width and peak separation in reversed-phase alternate-pumping (AP) recycle chromatography are found to be inconsistent with conventional chromatographic theory. These discrepancies are explained by subtle pressure-induced variations of solute retention that become amplified by AP recycling. The presence of these retention variations is demonstrated by multiply injecting a single solute into an AP system at offset times. As the serially injected peaks are recycled, the separation time between the peaks is shown to vary significantly, indicating that the retention of the solute is dependent upon the position of the peak. A new model of chromatographic retention that appropriately accounts for this variable retention is presented. When this retention model is applied to an AP system for the binary separation of phenylalanine and a pentadeuterated phenylalanine, the model accurately describes the experimentally observed progressions of peak width and peak separation. Furthermore, the retention model predicts that the improvement of resolution in AP recycling closely matches the expectations of conventional theory, so the effectiveness of AP recycling is not significantly compromised by the variations in retention.
反相交替泵送（AP）循环色谱中峰宽和峰间距的变化被发现与传统色谱理论不一致。这些差异是由压力引起的溶质保留的细微变化所解释的，这些变化通过AP循环而被放大。通过在不同时间将单一溶质多次注入AP系统，证明了这些保留变化的存在。随着连续注入的峰被循环，峰之间的分离时间显示出显著变化，表明溶质的保留取决于峰的位置。提出了一种新的色谱保留模型，该模型适当地考虑了这种可变保留。当将此保留模型应用于用于苯丙氨酸和五氘代苯丙氨酸二元分离的AP系统时，该模型准确地描述了实验观察到的峰宽和峰间距变化。此外，保留模型预测，AP循环中分辨率的提高与传统理论的预期密切匹配，因此保留变化不会显著损害AP循环的有效性。
