Department of Chemistry, Inha University, Incheon 402-751, South Korea.
J Chromatogr A. 2013 Aug 16;1303:9-17. doi: 10.1016/j.chroma.2013.06.016. Epub 2013 Jun 18.
Partially sub-2μm porous silica monolith particles have been synthesized by a renovated procedure and modified to polystyrene coated silica particles with excellent separation efficiency when used as chromatographic media. In the procedure of preparing silica monolith particles in this study, subtle control of formulation of the reaction mixture and multi-step heating followed by calcination, without any washing and sieving process, enabled formation of silica particles characterized by proper particle and pore size distribution for high separation efficiency. 3-Chloropropyl trimethoxysilane was used as the halogen terminal spacer to combine the initiator to silica particles. Uniform and thin coating of polystyrene layer on initiator attached silica particles was formed via reversible addition-fragmentation chain transfer (RAFT) polymerization. Micro-columns (1.0mm ID and 300mm length) were packed with the resultant phase and their chromatographic performance was elucidated by HPLC. A mobile phase of 60/40 (v/v) acetonitrile/water containing 0.1% TFA and a flow rate of 15μL/min were found to be the optimized conditions leading to number of theoretical plates close to 50,000 (165,000m(-1)). This is the very first study to get such highly efficient HPLC columns using a silica monolith particulate stationary phase.
部分亚 2μm 多孔硅胶整体颗粒已通过改进的方法合成，并修饰为聚苯乙烯涂覆硅胶颗粒，在用作色谱介质时具有出色的分离效率。在本研究制备硅胶整体颗粒的过程中，通过对反应混合物配方的细微控制和多步加热以及煅烧，而无需任何洗涤和筛分过程，形成了具有适当颗粒和孔径分布的硅胶颗粒，从而实现了高效率的分离。3-氯丙基三甲氧基硅烷被用作卤素末端间隔基，将引发剂结合到硅胶颗粒上。通过可逆加成-断裂链转移（RAFT）聚合，在附着引发剂的硅胶颗粒上形成均匀且薄的聚苯乙烯层。用所得相填充微柱（1.0mm ID 和 300mm 长），并通过 HPLC 阐明其色谱性能。发现流动相为 60/40（v/v）乙腈/水，含有 0.1%TFA，流速为 15μL/min 是优化条件，可得到接近 50,000（165,000m（-1））的理论塔板数。这是首次使用硅胶整体颗粒固定相获得如此高效的 HPLC 柱的研究。
