中孔复合锆-铝氧化物微球的制备及其正相色谱性能研究

复合氧化物通常表现出与单一氧化物不同的物理化学性质（如晶体结构、孔结构和表面性质等方面），已广泛用作催化剂、吸附剂和离子交换剂。1993年，Kaneko等采用共沉淀法制备的SiO2-TiO2，SiO2-Al2O3等复合氧化物的环境保护、痕量富集、氨基酸分离等方面取得较好的应用效果。但复合氧化物作为液相色谱固定相的研究很少报道。近年来，我们从制备、表征到正相、反相色谱性能等方面对MgO-ZrO2和SiO2-ZrO2复合氧化物作为色谱填料进行了系统的研究，发现MgO和SiO2掺杂可以有效地改善ZrO2的孔结构，提高柱效。本文用溶胶－凝胶方法制备了质量投料比m（硝酸铝）：m（氧氯化锆）＝20：64的ZrO2-Al2O3复合氧化物微球，考察酸腐蚀前后其晶形、表面酸碱性和孔容、孔径的变化，以及它们的正相色谱性能。

Preparation of Mesopore Zirconia-Alumina Composite and Its Application to Normal HPLC Support

Zirconia alumina composite was prepared as rigid microspheres by means of a sol gel process. Scan electron micrograph, electron spectroscopy, nitrogen adsorption, and potentiometric titration were used to characterize the zirconia alumina composite before and after acid etching. After the acid etching, the specific surface area of the zirconia alumina composite is about five times larger than that before acid etching; the molar ratio of Zr/Al and the acidity also increases, while the pore size decreases. The normal phase chromatographic performance of the zirconia alumina composite before and after acid etching was studied by using dichloromethane/cyclohexane, chloroform/cyclohexane, ethanol/cyclohexane as mobile phases. After the acid etching the zirconia alumina composite exhibited a higher column efficiency and different separation selectivity as compared with that before the acid etching. Basic compounds have a greater retention on the composite after the acid etching.