分子印迹固相萃取气相色谱-质谱法测定鸡蛋中三聚氰胺

Molecularly Imprinted Polymer Solid Phase Extraction Coupled with Gas Chromatography-Mass Spectrometry for the Determination of Melamine in Egg

关键词:  三聚氰胺  分子印迹聚合物  固相萃取  鸡蛋  气相色谱-质谱法

Key words:  melamine  molecularly-imprinted polymers  solid-phase extract  egg  gas chromatography-mass spectrometry

摘要:

以环丙氨嗪为虚拟模板分子，甲基丙烯酸为功能单体，乙二醇二甲基丙烯酸酯为交联剂，采用本体聚合法合成了对三聚氰胺具有良好交叉识别能力的分子印迹聚合物（MIP）。将其制备成固相萃取小柱，可有效分离、净化和富集鸡蛋中的三聚氰胺。提取的三聚氰胺进一步经Sylon BFTTM衍生后，采用气相色谱-质谱选择离子监测模式（SIM）测定。建立的基于分子印迹固相萃取气相色谱-质谱测定鸡蛋中三聚氰胺的确证方法，在25.0 ~ 500 ng/mL浓度范围内，线性良好（r＞0.99）；在50、500和1000 μg/kg添加水平，鸡蛋中三聚氰胺的平均回收率分别为82.5%、84.5%及81.4%，相对标准偏差小于10%；以3倍信噪（S/N）比计算，方法检出限(LOD)达10 μg/kg。

Abstract:

A molecularly imprinted polymer (MIP) using cyromazine as a mimic template, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linker was synthesized with bulk polymerization, and showed high cross-recognization to melamine. It was used to separate, enrich and cleanup melamine from egg via a molecularly imprinted solid-phase extraction (MISPE) protocol. For gas chromatography/mass spectrometry (GC/MS) analysis, extracted melamine was derived with Sylon BFTTM prior to selected ion monitoring detection in electron impact mode. The established method based on MISPE-GC/MS showed a good linear in the range from 25.0 to 500 ng/mL (r＞0.99), and the average recoveries of melamine from egg samples fortified at 50, 500 and 1000 μg/kg, were 82.5%, 84.5% and 81.4%, respectively, with coefficients of variation lower than 10%. The limit of detection obtained by MISPE-GC/MS was ca 10 μg/kg if calculated with a S/N ratio of 3.