黄芩苷键合硅胶固定相的制备和表征

Preparation and Characterization of a Baicalin-bonded Stationary Phase for High Performance Liquid Chromatograph

采用固液相表面连续反应法,以γ-氨丙基三乙氧基硅烷(TM-550)为偶联剂,制备了一种新型天然配体黄芩苷键合硅胶固定相(BBSP)。采用红外光谱、热重分析和元素分析进行结构表征。以不同结构的溶质为探针,初步评价了新固定相的基本色谱性能,探讨了色谱分离机理。结果表明,该固定相具有较弱的反相色谱性能,除疏水作用外,还存在较强的电荷转移和氢键作用。与ODS相比,协同作用使BBSP对芳香族化合物表现出较好的色谱分离选择性。由于极性的酰胺官能团和内部亲水性葡萄糖基的存在,能有效抑制亲硅醇基效应,从而能较好地分离碱性化合物。此外,实验发现新固定相对黄酮类化合物有很强的选择性保留,预示其在分离富集黄酮类化合物方面具有应用潜力。

The solid-liquid reaction method was used for the preparation of a new HPLC baicalin-bonded stationary phase （BBSP） via the amido linkage between coupling reagent γ-aminopropyhriethoxy silane （TM-550） and baicalin. Its structure of ligand was characterized by Fourier transform infrared spectroscopy, elemental analysis and thermal analysis etc.. The chromatographic performances of BBSP were preliminarily evaluated, and related retention mechanism was studied by using different solutes as probes. Meanwhile, the comparative study between BBSP and conventional octadecyl bonded silica （ODS） was also carried out under the same conditions. The results show that the new stationary phase has a relatively weak reversed phase chromatographic property. Besides hydrophobicity, BBSP can also provide various sites, such as hydrogen-bonding, π-π and π-π charge transfer interactions. Synergistic interactions improved the separation selectivity of BBSP for aromatic compounds and their positional isomers when compared with ODS. It can also be observed that the polar amide linkage and hydrophilic glucose residue can minimize the silane hydroxyl effect and improve the separation of basic nitrogen-containing compounds. Additionally, the new packing has strong affinity to flavonoids because of similar structures. BBSP can be used as enriching column packing for natural organic flavonoids from medicine herbs.