目的:建立中空纤维离心超滤前处理方法结合高效液相色谱法测定氧氟沙星凝胶剂的含量。方法:凝胶样品经中空纤维离心超滤技术进行纯化,滤除样品溶液中的高分子辅料后,采用HPLC法测定氧氟沙星凝胶剂的含量。采用C18柱,流动相为甲醇-水(30∶70,含0.5%的三乙胺,用磷酸调节p H至4.0),流速1.0 m L·min^(-1),柱温为室温,检测波长为293 nm。考察不同溶剂对样品含量测定的影响以及中空纤维膜的非特异性吸附。结果:以1 m L的0.1 mol·L^(-1)盐酸溶液中和凝胶,然后用水稀释制备样品溶液,采用聚偏氟乙烯中空纤维膜对样品进行超滤处理后,对氧氟沙星不存在非特异性吸附且有效去除了高分子凝胶辅料的干扰。氧氟沙星质量浓度在5.10~51.0μg·m L^(-1)范围内呈良好的线性关系(r=0.999 8);样品平均回收率为100.4%,RSD不大于1.7%。结论:本法经方法学验证,可用于氧氟沙星凝胶剂的含量测定。
Nanocrystalline BaTiO 3 powder was prepared by sol gel process from tetrabutyltitanium and hydrated barium hydroxide. The thermal decomposition reaction of the obtained gel has been studied by TG DTA and FTIR techniques. The nano powder had particle size of about 50 nm and was of cubic perovskite structure. The ceramics made from BaTiO 3 nano powder still maintained nano scale microstructure with size of about 80～150 nm after sintering at 1190～1330 ℃.
