一种聚合物包覆硅球整体微萃取柱的制备

利用甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,通过在装满硅球的石英毛细管内原位聚合制备了一种弱阳离子包覆硅球整体柱,确定了柱的最佳制备条件(反应温度60℃,反应时间4 h,单体体积分数25%,致孔剂组成为环己醇∶甲醇∶水的体积比为8∶1∶1).制得的整体柱作为固相微萃取介质对盐酸克伦特罗进行了在线富集,优化了影响萃取效率的参数(解吸液组成、进样体积、样品pH值),确定了乙腈-0.02 mol/L磷酸盐缓冲液(pH 2.7,二者体积比为40∶60)混合溶液作为解吸液、进样体积为40μL、样品pH值7.0为最佳萃取条件.并在最优条件下测得该方法的检出限为4.2 ng/mL(相当于噪音信号标准偏差的3倍),与直接进样相比,检测灵敏度约提高了300倍.

Preparation of A Polymer Silica-Microspheres-Encapsulated Monolithic Column for Microextraction

A weak cation silica-microspheres-encapsulated monolithic column was prepared by in-situ polymerization of methacrylic acid as a monomer and ethylene dimethacrylate as a cross-linking agent in a fused silica capillary packed with silica-microspheres.The optimal conditions(polymerization temperature:60℃,polymerization time:4h,the percentage of monomer:25%(v/v),the composition of porogens∶cyclohexanol∶methanol∶water=8∶1∶1) for preparing the column were established.The prepared column as a media for SPME was applied to enrich CLB online.Several parameters including composition of extraction mobile phase,extraction volumn and pH value of the sample matrix were optimized and the best extraction conditions were ACN-0.02mol/L phosphate buffer(pH 2.7)(volumn ratio 40∶60) mixture as the desorption solution,extraction volumn of 40μL and pH 7.0 of the sample matrix included.Under the optimal conditions the detection limit of 4.2ng/mL(S/N=3) wes obtained.Compared with direct injection,detection sensitivity was increased by about 300 times.