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采用层层自组装(LBL-SA)技术制备了新型的氧化铝包裹硅胶(Al2O3/Si O2)核-壳型色谱填料。对该填料进行了光电子能谱表征、扫描电镜表征、比表面孔径表征,结果表明Al2O3被成功的组装到了Si O2表面。考察了Al2O3/Si O2填料在正相色谱条件下对碱性、中性和酸性化合物色谱分离行为并与Si O2填料进行了比较性研究。结果表明,由于氧化铝表面的Lewis酸性位点的存在,相比较于Si O2填料而言,Al2O3/Si O2在分离碱性化合物和中性化合物时具有很大的优势,但是也是由于这些Lewis酸性位点,造成酸性化合物在Al2O3/Si O2柱上具有很长的保留时间和严重拖尾的峰形,流动相中少量乙酸的加入可以有效地掩盖Al2O3表面的Lewis酸性位点,减弱其对酸性化合物的吸附。
A novel alumina-encapsulated silica gel (Al2O3 / Si O2) core-shell chromatographic packing was prepared by the layer-by-layer self assembly (LBL-SA) technique. The filler was characterized by photoelectron spectroscopy, scanning electron microscopy and specific surface area characterization. The results showed that Al2O3 was successfully assembled on the Si O2 surface. The chromatographic separation behaviors of Al 2 O 3 / Si 2 O 4 under alkaline conditions were investigated and compared with that of Si O 2. The results show that Al 2 O 3 / Si 2 O 2 has great advantages in the separation of basic and neutral compounds compared to Si O 2, due to the presence of Lewis acid sites on the alumina surface, but also because of the Lewis acidity Site, resulting in acidic compounds on the Al2O3 / Si O2 column has a long retention time and severe tailing peak shape, the mobile phase of a small amount of acetic acid can effectively mask the Lewis acid sites on the Al2O3 surface, weakening its acidic Adsorption of compounds.