分子印迹固相萃取光谱法快速检测猪肉中左氧氟沙星

Determination of Levofloxacin in Pork by Molecularly Imprinted Solid Phase Extraction Spectroscopy

以表面接枝乙烯基的硅胶为载体,左氧氟沙星为模板分子,合成了选择性识别左氧氟沙星的印迹聚合物。使用元素分析、红外光谱对制备的聚合物进行表征,通过动态吸附及选择性吸附进行性能测定。结果表明,此印迹聚合物最大吸附量达56.33 mg/g,印迹因子为2.62。将所合成的硅胶表面左氧氟沙星分子印迹聚合物用于实验室自主开发的分子印迹固相萃取漫反射光谱检测装置,对左氧氟沙星进行定量分析。样品经此装置固相萃取后,不经洗脱,直接对固相萃取介质进行漫反射光谱测定,简化了操作过程,提高了灵敏度。标准曲线的回归方程为A=0.0496C+0.2412,线性范围为0.25~9.0 mg/L,相关系数R^2=0.9924,检出限为0.24mg/L。猪肉样品中的加标回收率为89.1%~92.0%,相对标准偏差RSD为3.4%~7.9%(n=3)。相比于传统的富集分离技术,本方法具有装置小型化和集成化、灵敏度和选择性高、成本低、简单快速等优点。

A printed polymer for selective identification of levofloxacin was synthesized on the surface of silica gel with levofloxacin as template molecule.The polymer was characterized by elemental analysis and infrared spectroscopy,and the properties of the polymer were determined by dynamic adsorption and selective adsorption.The results showed that the maximum adsorption capacity of the imprinted polymer was 56.33 mg/g and the imprinting factor was 2.62.The imprinted polymer was applied to quantitative analysis of levofloxacin with molecular imprinted solid phase extraction spectroscopy(SPES).The SPES was carried out in an elaborately designed device with which the interested analyte was extracted by the solid phase extraction medium and the diffuse reflectance spectrum was measured directly on the solid medium without elution.SPES has simplified the operation process and improved the sensitivity.The regression equation of the standard curve was A=0.0496 C+0.2412,the correlation coefficient(R 2)was 0.9924,the linear range was 0.25-9.0 mg/L,and the detection limit was 0.24 mg/L.The recoveries of determination of levofloxacin in Pork samples were 89.1%-92.0%,and the relative standard deviations(RSDs)of the three parallel tests were 3.4%-7.9%.Compared with the traditional enrichment and separation technique,this method developed here had some advantages such as miniaturization and integration,high sensitivity and selectivity,low cost,simple operation and rapid detection.