顶空固相萃取/表面增强拉曼法对挥发性农药的快速检测研究

Rapid Detection of Volatile Pesticides by Surface Enhanced Raman Spectroscopy with Headspace Solid Phase Extraction

该文开发了一种基于金纳米膜的快速检测挥发性农药地虫磷和福美铁的方法。将通过氧化还原法在不锈钢片表面制备的金纳米膜作为表面增强拉曼光谱(SERS)基底,结合顶空固相萃取法对挥发性农药地虫磷和福美铁进行检测。地虫磷和福美铁分别在75℃和55℃顶空固相萃取15 min得到显著的拉曼光谱信号,检出限(LOD)均为5×10^(-3)mg/L;地虫磷(999 cm^(-1))和福美铁(1 381 cm^(-1))的特征峰拉曼光谱强度与农药质量浓度在一定范围内呈线性关系,相关系数R~2分别为0.984 8和0.977 8。采用本法对果汁中的地虫磷和福美铁进行检测,回收率分别为93.3%~112%和92.5%~104%,相对标准偏差分别为4.1%~5.2%和3.4%~6.5%。该方法快速、灵敏,在挥发性农药检测方面具有潜在的应用价值。

In this paper,a fast and efficient method for the detection of volatile pesticides was developed,based on the gold nanofilm as surface enhanced Raman spectroscopy(SERS)substrate,which was prepared by redox reaction on the surface of stainless steel sheet.The volatile pesticides,i.e.fonofos and ferbam were detected by SERS with headspace solid phase extraction(SPE).Significant Raman signals were obtained by headspace solid phase extraction at 75℃and 55℃for fonofos and ferbam within 15 min,respectively.The limits of detection(LODs)were both 5×10^(-3) mg/L for these two pesticides.There were linear relationships between Raman spectrum intensities of the characteristic peaks(999 cm^(-1) and 1381 cm^(-1))and the pesticdes in a certain mass concentration ranges,with their correlation coefficients(R2)of 0.9848 and 0.9778,respectively.The recoveries for fonofos and ferbam in fruit juice were in the range of 93.3%-112%and 92.5%-104%,with relative standard deviations(RSDs)of 4.1%-5.2%and 3.4%-6.5%,respectively.The method is rapid and sensitive,which has a potential application value in the detection of volatile pesticides.