6-氨基青霉素烷酸分子印迹固相萃取柱在牛乳青霉素药物检测中的应用

Application of 6-APA molecular imprinted solid-phase extraction column in the detection of penicillins in milk

用实验室制备的分子印迹固相萃取柱完成市售牛乳样品中青霉素类药物的提取分离。以青霉素中间体6-氨基青霉烷酸（6-Aminopenicillanic acid,6-APA）为虚拟模板分子,甲酸作为致孔剂,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,合成6-APA分子印迹聚合物（molecular imprinted polymers,MIPs）,并对制备条件进行了优化,确定最佳的制备条件是模板分子∶功能单体∶交联剂（摩尔比）=1∶5∶30。采用选择性吸附试验比较青霉素类药物与恩诺沙星在该MIPs的吸附情况,结果表明：MIPs对青霉素类药物及其中间体具有特异性吸附;通过红外光谱和扫描电镜对MIPs结构和形貌进行表征,红外光谱分析可知,MIPs内部具有键合氢键的位点,观察MIPs扫描电镜图发现MIPs表面具有大量孔穴。使用该MIPs装填的固相萃取柱对牛乳样品进行预处理,并采用高效液相色谱进行检测,结果显示有牛乳样品中含有较高浓度6-APA;用空白样品添加不同浓度水平的3种青霉素类药物及6-APA混合溶液进行加标回收率实验,加标回收率为83.5%-87.3%,相对标准偏差（RSDs）为1.03%-7.35%。6-APA分子印迹固相萃取柱在复杂基质如动物源食品、水体、土壤样品的检测中具有广阔前景。

The homemade 6-APA molecular imprinted solid-phase extraction（ MISPE） column was applied in the extraction and separation of penicillins in market milk,largely enhancing the analytical speed. The molecularly imprinted polymers（ MIPs） was prepared using 6-aminopenicillanic acid which is the intermediate of penicillins as the virtual template,methylacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking monomer. The structure and morphology of molecularly imprinted polymers were characterized by Fourier Transform infrared spectroscopy（ FTIR） and Scanning Electron Microscope（ SEM）. The result of FTIR showed that there was hydrogen bonding sites inside of MIPs. The result of SEM indicated that there were large amounts of holes on the surface of MIPs. The selective adsorption ability of MIPs was detected by specific adsorption experiment,and it illustrated that the MIPs had selectivity for Penicillin drugs. The solid phase extraction（ SPE） column packed with MIPs was used for pretreatment of milk sample,coupled with HPLC detection. The results came out that one sample contained high content of 6-APA,without other three PENs. The recovery experiment was conducted at 3 different spiked levels,and the results showed the recovery rate was 83. 5% - 87. 3%. The 6-APA MISPE column also has broad prospects in the detection of complex matrices like animal food,water samples and soil samples.