核壳硅碳复合微球固定相的制备及其在糖类分离中的应用

采用一步法在二氧化硅(SiO₂)表面涂覆酚醛树脂聚合物(PF),并在氮气气氛下碳化,制备了核壳硅碳复合微球(Sil@MC)固定相。实验对Sil@MC固定相进行形貌观察和孔结构分析,表明制备出的Sil@MC固定相具有良好的单分散性,包覆后的Sil@MC材料比表面积为302 m²/g,平均孔径为9.5 nm,孔容为0.63 cm³/g,说明通过共聚反应成功地将碳材料固定在二氧化硅上。将制备的Sil@MC材料作为HPLC固定相,采用匀浆法装柱,以乙腈-水(含0.1%(v/v)甲酸)作为流动相,发现Sil@MC色谱柱在高效液相色谱-质谱中可以实现4种极性糖类化合物(D-(+)-氨基葡萄糖盐酸盐、葡萄糖、D-(+)-海藻糖二水合物和棉子糖)的分离,然而未涂覆酚醛树脂的SiO₂材料未能对这4种极性糖类化合物实现分离。实验进一步对Sil@MC固定相的性能进行了评价,代表性的低聚糖异构体松三糖和棉子糖、耐斯糖和水苏糖及乳寡糖异构体3'-唾液酸乳糖和6'-唾液酸乳糖、乳-N-四糖和乳-N-新四糖在Sil@MC色谱柱中被成功分离,峰形良好,展现了基于酚醛树脂衍生碳的核壳硅碳复合材料在在极性化合物色谱分离方面具有应用潜力。

Preparation of core-shell silica-carbon composite microspheres stationary phase and application in saccharide separation

In this study, core-shell mesoporous silica-carbon composite microspheres (Sil@MC) were prepared by one-step coating of the phenol formaldehyde polymer (PF) on SiO₂ surface and by carbonizing the PF polymer under nitrogen atmosphere. The morphology observation of the Sil@MC stationary phase showed that it had good monodispersity. Surface area (302 m²/g), mean pore diameter (9.5 nm), and pore volume (0.63 cm³/g) of Sil@MC materials were also measured by pore structure analysis. The results showed that the Sil@MC was successfully immobilized on the silica particles via copolymerization and carbonization. As a stationary phase of HPLC, the Sil@MC column was filled by a slurry method. The Sil@MC materials formed after calcination of SiO₂ coated with phenolic resin could be used for the separation of four polar sugar compounds (D-(+)-glucosamine hydrochloride, glucose, D-(+)-trehalose dihydrat and raffinose) with the mobile phase of acetonitrile-water (containing 0.1% (v/v) formic acid). However, the material formed by calcinating SiO₂ without coating phenolic resin could not separate these polar sugar compounds by HPLC-MS. Finally, the representative oligosaccharide isomers of raffinose, melezitose and stachyose, nystose, and human milk oligosaccharide isomers, such as 3'-sialyllactose, 6'-sialyllactose and lacto-N-newtetraose, lacto-N-tetraose, were successfully separated by the Sil@MC column with good peak shapes. The results demonstrates that silica-carbon composites derived from phenolic resin have potential application in polar compounds chromatographic separation.