三元醇丙烯酰胺键合色谱固定相的制备及评价

利用巯基与乙烯基的"点击化学"反应合成了一种新型含多羟基的硅烷偶联剂,再将其与硅胶反应制得含多羟基的亲水固定相。经过元素分析表征证明多羟基官能团已成功键合到硅胶表面。采用一系列不同性质的标准物质考察了亲水色谱模式下固定相的溶质保留机理。由于固定相结构中既具有极性多羟基官能团,也有短的疏水碳链,因此固定相兼具疏水性与亲水性。将此固定相成功应用于亲水与反相色谱两种模式,并对比了两种模式下流速对柱效的影响。最后将固定相应用于烷基苯、水溶性维生素以及核苷的分离中,取得了较好的分离效果,证明了固定相良好的应用前景。

Preparation and evaluation of N-acryloyltris(hydroxymethyl) aminomethane-bonded chromatographic stationary phase

The present study described the preparation of N-acryloyltris(hydroxymethyl) aminomethane-bonded silica (NAS) stationary phase based on "thiol-ene" click chemistry. The composition of the surface grafts of NAS stationary phase was determined by elemental analysis and the results demonstrated the successful introduction of the N-acryloyltris (hydroxymethyl) aminomethane groups to the silica surface. Similar elemental composition of three batches of the NAS stationary phases exhibited good reproducibility of the preparation strategy. A set of standard compounds were employed to investigate the retention mechanism of the NAS stationary phase by three different empirical equations. The results indicated the retention of the tested analytes on the NAS stationary phase was based more on a mixed-mechanism rather than a simple partitioning or adsorption process. Eight compounds were selected to study the hydrophobic and hydrophilic properties of the NAS stationary phase in mobile phase with different ACN contents. Due to its hydrophilic triolacrylamide groups and short hydrophobic alkyl chains, the NAS phase was successfully applied in both reversed-phase liquid chromatography (RPLC) mode and hydrophilic interaction liquid chromatography (HILIC) mode. The influence of flow rate on the column efficiency was compared in these two modes. In contrast to RPLC columns, the overall heights equivalent to a theoretical plate (HETP) in HILIC is weakly dependent on the retention of the analyte and the HETP curve is much flatter in RPLC than in HILIC at larger reduced velocities. Furthermore, the separation of alkylbenzenes, nucleosides and nucleobases, water-soluble vitamins was achieved on the new stationary phase, demonstrating the excellent application potential.