以UO22+为印迹离子,偶氮二异丁腈(AIBN)为引发剂,邻苯二酚-UO22+-4-乙烯基吡啶三元配合物为模板,与苯乙烯单体、交联剂二乙烯基苯在甲醇溶液中通过共聚反应制备了UO22+印迹聚合物微球。该印迹聚合物微球经6mol/L HCl处理后留下与铀酰离子大小相匹配的空穴,对水溶液中微量铀有富集作用,在pH=5~7及吸附时间在20min以上时,该印迹聚合物微球对水溶液中微量铀的吸附率可达99%以上,且具有良好的选择性;HCl浓度在1.0mol/L以上,淋洗体积为聚合物体积的5倍以上,淋洗时间在20min以上时洗脱率可达99%以上。将其应用于卤水中微量铀的测定,与标准方法相比较,所得结果令人满意。
Uranyl ion imprinted polymer beads were prepared by the copolymerization of styrene monomer and divinyl benzene as crosslinking agent in methanol solution,with the UO2+2-o-dihydroxybenzene-4-vinyl pyridine ternary complex as template,the 2,2′-azo-bis-isobutyronitrile as initiator and UO2+2 as the imprinting ion.The uranyl ions were removed from the polymer beads by treating with 6 mol/L HCl,leaving behind cavities that match uranyl ion in size.The treated polymer beads can preconcentrate uranyl ions from dilute aqueous solutions.The adsorption efficiency can reach 99% or above with good selectivity when pH is in the range of 5-7 and the adsorption time is more than 20 min.The elution rate can reach above 99% under the conditions of concentration of HCl being above 1.0 mol/L,elution time more than 20 min and the elution volume more than 5 times the volume of ion imprinted polymer.The uranyl ion imprinted polymer beads have been successfully applied to determine micro-uranium in brine samples.The results are satisfactory compared with NBS method.