Development of novel organic phases for high selective and sensitive HPLC by controlled surface modification

本课题旨在开发一种新型的高选择性高效液相色谱包装材料。为了实现这一目的，我们提出了两个目标：(1)物理控制表面形态；(2)通过接枝聚合对载体材料进行化学改性和HPLC应用。我们建立了一种用二氧化硅粒子-层壳制备核壳粒子的新方法。这种方法有几个优点，可以强调如下：(a)核壳颗粒可以很容易地通过一锅悬浮聚合制备。(b)合成壳通过共价键稳定固定。(c)通过适当选择二氧化硅颗粒的直径和组合，可以调整壳体结构从单层到多层。(d)利用多孔二氧化硅颗粒和去除二氧化硅颗粒，可以形成凹痕结构表面。为了实现二氧化硅表面的化学功能化，研究了一种聚合物接枝方法。采用杂环结构的乙烯基单体，如咔唑和恶唑。所得杂化产物在高效液相色谱中表现出良好的分离能力，尤其是对多芳烃的分离能力。研究还表明，不仅可以通过选择单体，还可以通过选择聚合方法来调节选择性。在含有β-和γ异构体的生育酚的基线分离中观察到最成功的结果。

This research project aims to develop a new class of HPLC packing materials with high selectivity. To accomplish this purpose, we proposed two goals :(1) Physical control of surface morphology and (2) chemical modification by graft polymerization on supporting materials and HPLC applications.1. We established a new method for creation of core-shell particles with silica particles-layer shells. This method has several advantages that can be emphasized as follows :(a) the core-shell particles can be readily prepared by one-pot suspension polymerization.(b) The resultant shell is stably immobilized by covalent bonding.(c) By proper choosing the diameter and combination of silica particles, the shell structures can be adjusted from single-to multi-layers.(d) By using porous silica particles and removal of silica particles, the dimple structural surface can be created.2. For chemical functionalization of silica surface, a polymer-grafting method has been investigated. Vinyl monomers with heterocyclic structures such as carbazole and oxazole were used. The resultant hybrids showed excellent separation ability in HPLC especially for polyaromatic hydrocarbons. It has also been established that the selectivity can be tuned by not only choosing a monomer but also polymerization method. The most successful results were observed in the base-line separation of tocopheroles containing β- and γisomers.