噻菌灵农药的表面增强拉曼光谱分析

摘要

利用表面增强拉曼光谱技术（SERS）分析噻菌灵农药的拉曼特征峰。采用微波法制备银溶胶表面增强基底，利用激光显微共焦拉曼光谱仪分别采集514．5和785 nm激发波长下的噻菌灵农药拉曼光谱，解析不同激发波长下的拉曼特征峰并进行比较。结果表明：不同激发波长下噻菌灵的拉曼峰强度和拉曼频移差异较大，514．5 nm激发波长下的782和1012 cm－1最强，是C—H 变形振动较强特征峰，而785 nm激发波长下的1284，1450和1592 cm－1最强，是环振动和 CN 伸缩振动较强特征峰。对比分析各个激发波长下噻菌灵的SERS谱图，找到了噻菌灵农药的5个较强特征拉曼峰：782，1012，1284，1450和1592 cm－1。这些特征峰可作为食品及农产品中噻菌灵农药残留定性定量判别的依据。%Surface-enhanced Raman spectroscopy (SERS)technique was used to analyze the Raman peaks of thiabendazole pesti-cides in the present paper.Surface enhanced substrates of silver nanoparticle were made based on microwave technology.Raman signals of thiabendazole were collected by laser Micro-Raman spectrometer with 514. 5 and 785 nm excitation wavelengths,re-spectively.The Raman peaks at different excitation wavelengths were analyzed and compared.The Raman peaks 782 and 1 012 at 785 nm excitation wavelength were stronger,which were C—H out-of-plane vibrations.While 1 284,1 450 and 1 592 cm-1 at 514. 5 nm excitation wavelength were stronger,which wereνring and C N stretching.The study results showed that the inten-sity of Raman peak and Raman shift at different excitation wavelengths were different.And strong Raman signals were observed at 782,1 012,1 284,1 450 and 1 592 cm-1 at 514. 5 and 785 nm excitation wavelengths.These characteristic vibrational modes are characteristic Raman peaks of carbendazim pesticide.The results can provide basis for the rapid screening of pesticide residue in agricultural products and food based on Raman spectrum.