多壁碳纳米管固相萃取/气相色谱-质谱测定蔬菜中的苯醚甲环唑农药残留

Determination of difenoconazole in vegetables samples by gas chromatography-mass spectrometry using multi-walled carbon nanotubes as solid-phase extraction sorbent

以多壁碳纳米管(MWCNTs)为固相萃取材料,建立了蔬菜中苯醚甲环唑农药残留的气相色谱-质谱联用(GC-MS)分析方法。样品经乙酸乙酯匀浆提取后,以MWCNTs固相萃取柱净化,用GC-MS进行检测。研究了不同提取溶剂和MWCNTs的量对提取净化效率的影响。结果表明:在最优实验条件下,苯醚甲环唑在0.005~2.0μg/m L范围内呈良好的线性关系,相关系数为0.9997,检出限为0.001 mg/kg,空白蔬菜样品在0.01、0.10、1.00μg/m L 3个加标水平下的回收率在84.2%~111.3%之间,相对标准偏差(n=5)为5.3%~11.9%。该方法灵敏度高,选择性好,抗干扰能力强,适合蔬菜中苯醚甲环唑残留量的定性确证分析和定量分析。

A method based on multiwalled carbon nanotubes（ MWCNTs） as the solid phase extraction material had been developed for the determination of difenoconazole in vegetables by gas chromatography-mass spectrometry（ GC-MS）.The samples were extracted with ethyl acetate,purified by MWCNTs solid phase extraction; and determined by GC-MS. Effects of different extraction solvents and amount of MWCNTs on the determination of difenoconazole were investigated. The results showed that difenoconazole had a good linearity in the range of 0.005 ~ 2.0 μg/m L and the correlation was 0.9997 under the optimal conditions.The limit of detection for difenoconazole was 0.001 mg/kg.Tests of recoveries were made by the addition to blank vegetable sample at three spiked levels of 0.01,0.10 and 1.00 μg/m L,and the recoveries were in the range of 84.2% ~111.3% with relative standard deviations（ RSD,n = 5） of 5.3% ~ 11.9%. Therefore,the developed method is suitable for determination of difenoconazole in vegetables qualitatively and quantitatively with satisfactory sensitivity,selectivity,accuracy and precision.