CHEMICALLY MODIFIED SILICA AS BONDED PHASE SUBSTRATE FOR CHROMATOGRAPHY

拟议项目的主要目标是推进 现代层析方法通过增强的 对硅烷化固定相表面结构的理解 改进的粘结相材料的后续开发。最新进展 生物医学研究与选择性和敏感性密切相关。 由于化学的复杂性，层析方法的局限性 生物基质的重要性和样品分离的必要性。 分析。用改进的层析技术开发载体材料 性能要求对固定相表面有清晰的了解 结构和有问题的表面物种的存在。这项研究 本提案中描述的内容最终将有助于 对未改性和硅烷化二氧化硅表面结构的理解 将促进未来粘合阶段性能的进步 支撑物。研究的具体目标将是：1)研究 热处理对多孔性多孔硅凝胶的影响 直径，2)研究表面硅烷化的程度和如何 受不同试剂(烷氧基、氯和有机氨基硅烷)的影响， 孔径、硅烷烷基链长、胺催化剂、表面 吸附水等，以及3)比较研究其动力学。 硅烷试剂在溶液和气相中的硅烷化反应 阶段。将完成对改性表面的表征 使用变温漫反射傅里叶变换红外光谱(VT-FTIR) 漂移物)与可加热、可疏散的样品室相结合。 通过漂移分析将确保表面物种完好无损 不受样品制备程序的影响。样品室的使用 将允许进行现场环境控制研究，从而探测 分子可以与表面位置相互作用。定性研究将 阐明附着物的结构性质和表面浓度 硅烷的结构性质、浓度和相对含量 表面硅醇(SiOH)物种的酸度。

The primary objective of the proposed project is to advance the capabilities of modern chromatographic methods through an enhanced understanding of silylated stationary phase surface structure and the subsequent development of improved bonded phase materials. Advances in biomedical research are closely tied to the selectivity and sensitivity limitations of chromatographic methods because of the chemical complexity of biological matrices and the necessity for sample separation prior to analysis. Developing support materials with improved chromatographic performance requires a clear understanding of stationary phase surface structure and the existence of problematic surface species. The research described in this proposal will ultimately contribute to the understanding of unmodified and silylated silica surface structure which will facilitate future advances in the performance of bonded phase supports. Specific goals of the research will be; 1) to study the effects of thermal treatment on porous silica gels having variable pore diameter, 2) to study the extent of surface silylation and how it is affected by different reagents (alkoxy, chloro, and organoaminosilanes), pore diameter, silane alkyl chain length, amine catalysts, surface adsorbed water, etc., and 3) to comparatively study the kinetics of the silylation reaction using silane reagents in both solution and gaseous phases. Characterization of the modified surfaces will be accomplished using variable-temperature diffuse reflectance FTIR spectroscopy (VT- DRIFTS) in conjunction with a heatable-evacuable sample chamber. Analysis by DRIFTS will insure that surface species are intact and unaltered by the sample preparation procedure. Use of the sample chamber will allow for in-situ environmentally controlled studies whereby probe molecules can interact with surface sites. Characterization studies will elucidate the structural nature and surface concentration of attached silanes, as well as the structural nature, concentration and relative acidity of surface silanol (SiOH) species.