三聚氰胺分子印迹预组装体系紫外光谱研究

Ultraviolet Spectroscopic Investigations into Melamine Molecular Imprinting Pre-assembly System

通过对三聚氰胺(MEL)与甲基丙烯酸(MAA)、丙烯酰胺(AM)和亚甲基丁二酸(IA)3种单体在甲醇中相互作用的分子印迹预组装体系的紫外光谱研究发现,MEL与3种单体之间均产生了氢键相互作用;其中,AM对体系影响最大,MAA次之,IA最弱。氢键使MEL的三嗪环共轭双键和发色团取代的芳核产生π—π*电子跃迁,使各组装体系最大吸收波长红移。实验推测出MEL与3种单体形成最佳模板-单体复合物的浓度比分别为:cMEL:cMAA=1:6、cMEL:cAM=1:8、cMEL:cIA=1:8。差示紫外光谱表明:3个预组装体系中1个MEL分子分别与2个MAA分子、3个AM分子、1个IA分子各自形成MEL-2MAA、MEL-3AM和MEL-IA型复合物。

According to the ultraviolet spectrum（UV） of melamine（MEL） molecular imprinting pre-assembly system,hydrogen-bonding interactions existed between melamine（MEL） and three monomers including methyl acrylic acid（MAA）,itaconic acid（IA） and acrylamide（AM）.AM revealed the greatest impact on the system,the second place was taken by MAA,and IA had the smallest effect.π-π＊ electron transitions of the conjugated double bonds in the triazine ring and the aromatic nucleus replaced by chromophore in MEL took place under hydrogen-bonding interactions and therefore maximum absorption wavelength of each pre-assembly system revealed a red shift.The optimal molarity ratios between MEL and three monomers were c（MEL）： c（MAA） = 1：6,c（MEL）： c（AM） = 1：8,and c（MEL）： c（IA） = 1：8.Differential ultraviolet spectral analysis showed that one MEL molecule could be conjugated with two MAA molecules,three AM molecules and one IA molecule to form their own complex types in three pre-assembled systems.