摘要
以三聚氰胺(MEL)为模板分子,采用沉淀聚合方法研究了以衣康酸(IA)为多齿功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂时,组分之间摩尔比对三聚氰胺印迹聚合物(MIP)选择性的影响.研究发现,当MEL与IA摩尔比为1∶1.5时,所合成的MIP对三聚氰胺具有最佳选择性,选择性系数k=10.41(以三聚氰酸为对照物).此时IA的识别位点(羧基)与三聚氰胺的可识别位点(胺基)摩尔比为1∶1,因此,不会出现由过量功能单体引起的非特异性吸附.Scatchard分析结果表明,这种MIP能够在更宽的三聚氰胺浓度范围(1~100 mg/L)内只表现出特异性吸附.以灭蝇胺为对照物时,kNIP<1但kMIP>1,该结果证明MIP对分子的形状有良好的识别能力.最后,以制备的MIP为固相萃取吸附剂,结合高效液相色谱/紫外检测器(HPLC/UV)建立了三聚氰胺测定方法.当牛奶(奶粉)中MEL的加标浓度分别为15,600和4500μg/L(μg/kg)时检测的加标回收率为92.34%~109.4%.
A molecularly imprinted polymer(MIP)was prepared using melamine(MEL)as template,itaconic acid(IA)as functional monomer and ethylene glycol dimethacrylate(EGDMA)as cross-linker.The effect of molar ratio among these components on the selectivity of MIP was investigated.It is found that the prepared MIP presents the best selectivity to MEL when molar ratio of MEL to IA is 1∶1.5.The selectivity coefficient(k)of the synthesized MIP to MEL is 10.41(CYA as control).Since the molar ratio of carboxyl groups(recognition sites)of IA and amino groups(recognizable groups)of MEL is exactly 1∶1,the non-specific adsorption caused by excessive functional monomers will be avoided.Scatchard analysis indicates that MIP only exhibits specific binding to MEL within the concentration range from 1 to 100 mg/L of MEL.On the other hand,when CYR is used as the control,the k NIP is less than 1 but the k MIP is greater than 1.This result implies the synthesized MIP has good discriminating ability for the shape of molecules.Using the prepared MIP as the adsorbent of solid phase extraction(SPE),a method of MISPE hyphenated to high performance liquid chromatography with UV detector(MISPE-HPLC/UV)was established for determination of melamine.The recoveries of MEL in the spiked milk and milk powder samples vary from 92.34%to 109.4%.
作者
王晓如
张娜
邢钧
WANG Xiaoru;ZHANG Na;XING Jun(College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,China;Researcher of Analytical Technology Development Unit,Hec Pharm Co.Ltd.,Yidu 443300,China)
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第7期1521-1530,共10页
Chemical Journal of Chinese Universities
关键词
分子印迹
多齿功能单体
衣康酸
三聚氰胺
固相萃取
Molecular imprinting
Multidentate functional monomer
Itaconic acid
Melamine
Solid phase extraction