光聚合整体式咖啡因印迹毛细管柱的制备及分离性能

分子印迹技术作为一种制备对目标分子具有专一识别能力的功能高分子的方法 ,近年来在化学化工、生物化学与生物技术的许多领域中得到广泛应用 [1～ 4 ] .分子印迹技术与微分离方法 (包括微柱液相色谱、毛细管电泳、毛细管电色谱和芯片分离等 )结合已引起人们极大的兴趣和关注[5,6] .毛细管柱是毛细管电色谱和微柱液相色谱的关键部件 ,目前普遍使用的是烷基键合硅胶微粒的填充柱 ,存在制备时须烧塞和填充两大困难 ,以及使用时易产生气泡和易折断等缺点 .将含被识别分子 (印迹分子 )、交联剂、溶剂、功能单体和引发剂的混合液注入毛细管 ,经光…

Molecularly Imprinted Polymer Monoliths Prepared in Capillaries by Photoinitiated in situ Polymerization for the Screening of Caffeine

Anovel and simple method for the in situ preparation of monolithic molecularly imprinted flowthrough polymers is described. The polymers were prepared inside UVtransparent fused silica capillaries by photoinitiated polymerization of a mixture of caffeine as the template, methacrylic acid as the functional monomer , trimethylolpropane trimethacrylate as the crosslinking agent in the presence of a porogenic solvent consisting of toluene and isooctane . Scanning electron micrographs confirmed the presence of the clusters of globules separated by large pores on the monolithic structure. The effectiveness of the imprinted polymer monolithic column was demonstrated in microcolumn liquid chromatography(μHPLC)mode by the screening of caffeine from a mixture of four structural analogues, the resolution factor Rs of 2.57 and 2.97 for the separation of caffeine against theophylline and theobromine, respectively, were obtained, while the nonimprinted column showed no specific selectivity. It is considered that the template was effectively imprinted in monolithic polymer by photoinitiated in situ polymerization at a low temperature. Several factors such as the molar ratio of the functional monomer to the imprint molecule and polymerization time affecting the flowthrough properties of a MIPcolumn were also investigated. The results show that the obtained columns exhibit higher resolution and column efficiency against the structural analogues than do columns packed with MIPprepared by bulk polymerization and columns packed with continuous molecularly imprinted polymer rod prepared by in stiu method.