山药中有机农药残留的表面增强拉曼光谱检测

Detection of Residual Organic Pesticides in Yam by Surface Enhanced Raman Spectroscopy

山药是一种富含多种物质的中药材,确保山药的安全使用具有重要的意义。使用Gaussview/Gaussian09w软件对农药倍硫磷、三唑磷和福美双进行理论计算,结合农药标准溶液的表面增强拉曼光谱(SERS),确定了三种农药的拉曼特征峰。利用自组装共聚焦显微拉曼光谱仪,以金纳米溶胶作为SERS的增强基底,对中药材山药中倍硫磷、三唑磷、福美双农药残留进行了研究。实验优化了待测农药、盐酸、金溶胶粒子体积配比。实验结果表明:倍硫磷农药的拉曼谱峰带在717,1050,1221 cm^(-1)附近,最低检测限达到1 mg⋅L^(-1),且在5~15 mg⋅L^(-1)范围内的拉曼峰强度与倍硫磷浓度的线性度(R)为0.9762;三唑磷的拉曼谱峰带在611,978,1001,1321,1408,1597 cm^(-1)附近,最低检测限达到1 mg⋅L^(-1),在5~9 mg⋅L^(-1)范围内的R为0.9087;福美双的拉曼谱峰带在556,865,1146,1506 cm^(-1)附近,最低检测限达到0.1 mg⋅L^(-1),且在0~20 mg⋅L^(-1)范围内的R为0.9905。以金纳米溶胶作为SERS增强基底的拉曼光谱检测技术有望实现对中药中农药残留的现场快速检测。

Yam is a kind of traditional Chinese medicine which contains many substances.It is of great significance to ensure the safe use of yam.In this article,the Raman peaks of the three pesticides,i.e.,fenthion,triazophos,and thiram,were calculated by Gaussview/Gaussian09w.By combining with the surface-enhanced Raman spectroscopy(SERS)of the standard pesticide solutions,the Raman characteristic peaks of these three pesticides are determined.The pesticide residues of fenthion,triazophos,and thiram in yam were studied by using the selfassembled confocal Raman microscope as the detection device,and the gold nanosol was used as the enhanced substrate of SERS.The volume ratio of pesticides,hydrochloric acid,and gold sol particles was optimized experimentally.The experimental results show that the Raman peak bands of fenthion pesticide are around 717,1050,and 1221 cm^(-1),the lowest detection limit is 1 mg⋅L^(−1),and the linearity R between the intensity of Raman peak and fenthion pesticide concentration is 0.9762 within the fenthion concentration range of 5‒15 mg⋅L^(−1).The Raman peak bands of triazophos are around 611,978,1001,1321,1408,and 1597 cm^(-1),the minimum detection limit is 1 mg⋅L^(−1),and the linearity is 0.9087 within the concentration range of 5‒9 mg⋅L^(−1).The Raman peak bands of thiram are around 556,865,1146,and 1506 cm^(-1),the minimum detection limit is 0.1 mg⋅L^(−1),and the linearity is 0.9905 within the concentration of 0‒20 mg⋅L^(−1).It is expected that the rapid on-site detection of pesticide residues in traditional Chinese medicines can be realized by using gold as the enhanced substrate for SERS.