氮氧化硅色谱固定相材料的制备及性能研究

Solubility in basic solution and asymmetric peaks for basic compounds in RP separations continue to be problematic for silica-based stationary phase. In our previous work, silicon oxynitride (SiON) stationary phase with high nitrogen content exhibited substantial improvement of chemical stability under high-pH mobile phase condition relative to bare silica column. The reactivity of surface Si–NH2 and Si–NH–Si groups endows SiON stationary phase flexible surface tailorability and opens up a broad applicability in different separation modes through modification using different functionalized reagents. Here, SiON microspheres modified with different groups are designed as HPLC packing material. The chromatographic evaluation of bare and bonded SiON stationary phase will be performed on analytes with different structure and charge properties as probes, and effects of mobile phase composition, such as the use of salt, pH modification, and temperature, on the retention properties on the SiON stationary phase will be studied. The stability of SiON material with different content of N element in different mobile phase condition will be investigated, which will establish the influence of N element in the framework for the stability of SiON material. The effects of structure of surface polar groups, linkage, hydrophilicy, carbon chain, and electric charge distribution on the separation performance will be summarized in the project, which will accordingly contribute to optimize and design the structure of SiON-based HILIC and RPLC packing materials. Based on the novel SiON HPLC stationary phase, very efficient chromatographic separation and purification method can be developed. Due to the high-pH stability and different selectivity, porous SiON-based stationary phases hold great promise as HPLC packing material complementary to the commonly used silica-based stationary phases.

针对硅胶在碱性条件下易溶解以及键合硅胶对碱性化合物反相色谱分离的峰拖尾问题，本项目拟根据氮氧化硅材料具有比硅胶更高的高pH稳定性及表面可修饰的特点，开展氮氧化硅色谱固定相材料的制备及色谱性能研究，在前期初步研究基础上发展以亲水作用和反相色谱为核心，电荷作用为补充的氮氧化硅基质色谱固定相材料。研究考察氮氧化硅色谱固定相稳定性，揭示硅胶骨架中N元素引入对氮氧化硅稳定性的影响。考察不同性质和电荷化合物分别在氮氧化硅色谱固定相上亲水和反相色谱分离模式下的色谱保留规律，建立氮氧化硅基质固定相材料性质-色谱分离性能之间的构效关系。从氮氧化硅基质固定相材料表面亲水性、疏水性、键合相表面构象和组成、表面电荷分布等方面进行优化，实现对氮氧化硅色谱固定相材料表面性质的调控。构建碱性条件下稳定存在的氮氧化硅基质色谱分离体系，实现对碱性化合物色谱分离的良好峰形，增强分析物的色谱保留和分离选择性。

针对硅胶在碱性条件下易溶解以及键合硅胶对碱性化合物反相色谱分离的峰拖尾问题，本项目根据氮氧化硅材料具有较硅胶更高的高pH稳定性及表面可修饰的特点，开展了氮氧化硅色谱固定相材料的制备及色谱性能研究，系统研究了未键合氮氧化硅材料的表面性质、稳定性以及色谱保留规律，从材料表面亲水性、疏水性、键合相表面构象和组成以及表面电荷分布等方面设计和优化新型氮氧化硅色谱固定相材料。进一步发展了以亲水作用为核心、电荷作用为补充的极性基团修饰氮氧化硅基质固定相，以寡糖、糖苷、碱性化合物、氨基酸、多肽等样品为模型化合物对极性基团修饰的氮氧化硅固定相进行色谱保留规律研究。发展了疏水表面的高性能氮氧化硅基质反相色谱分离材料，以酸性、中性、碱性等小分子化合物、多肽和蛋白质等为模型样品对其色谱保留规律进行研究。本项目执行三年，超额完成了申请书和任务计划书所提出的研究方案和实验预期，相关研究工作已经发表4篇文章，授权国际专利1件，培养4名硕士生。本项目从氮氧化硅基质固定相材料表面亲水性、疏水性、键合相表面构象和组成以及表面电荷分布等性质进行优化，实现了对氮氧化硅色谱固定相材料表面性质的调控，发展了高稳定性和色谱选择性的氮氧化硅基质固定相材料，建立了高效的基于氮氧化硅基质色谱分离材料的色谱分离体系。