液相色谱-串联质谱法测定蔬菜中烟碱类化合物的基质效应研究

Matrix effects of neonicotinoid pesticides in vegetables with liquid chromatography-tandem mass spectrometry

中文关键词:  基质效应  液相色谱-串联质谱法  蔬菜  烟碱类化合物  农药残留

英文关键词:matrix effects  liquid chromatography-tandem mass spectrometry  vegetables  neonicotine compound  pesticides

中文摘要:

      目的 建立蔬菜中6种烟碱类化合物的QuEChERS与液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry, LC-MS/MS)相结合的残留检测方法, 研究洋葱、蒜薹、姜、胡萝卜、黄瓜和白菜6种基质对烟碱类化合物的基质效应, 并探讨基质种类、农药种类和基质浓度对基质效应的影响。方法 样品经15 mL乙腈提取, 50 mg GCB、200 mg C18和150 mg PSA粉净化, LC-MS/MS法测定并计算基质效应。结果 农药在0.005~0.2 μg/mL范围内线性关系良好, 相关系数0.9910~0.9991, 平均回收率78.9%~112.7%, 相对标准偏差均小于10%。呋虫胺、噻虫嗪、噻虫胺在6种蔬菜中主要呈现基质抑制效应, 吡虫啉在黄瓜和白菜中部分浓度表现基质增强效应, 其余主要为基质抑制效应; 啶虫脒和烯啶虫胺在蒜薹和姜中呈基质抑制效应, 在其他基质中主要表现明显的基质增强效应。结论 该方法在检测蔬菜中的烟碱类化合物时, 存在不同程度的基质效应, 基质种类、农药分子结构和基质浓度均会影响基质效应强度, 所以实际检测中必须考虑基质效应, 建议采用基质加标曲线定量。

英文摘要:

      Objective To establish a method for determination of 6 kinds of neonicotinoid pesticides with QuEChERS and liquid chromatography-tandem mass spectrometry (LC-MS/MS), discuss the matrix effects in onion, garlic scape, ginger, carrot, cucumber and cabbage, and discuss the influences of matrix type, matrix concentration and pesticide concentration for the matrix effects. Methods The samples were extracted by acetonitrile, cleaned up with GCB (50 mg), C18 (200 mg) and PSA (150 mg), analyzed by LC-MS/MS, and then the matrix effects were calculated. Results Six pesticides had good linear relationships in the range of 0.005-0.2 μg/mL, and the correlation coefficients were 0.9910-0.9991. The recoveries were 78.9%-112.7% with the relative standard deviations (RSDs) less than 10%. Dinotefuran, thiamethoxam, clothianidin showed matrix inhibitory effect in 6 vegetables, some concentrations of imidacloprid showed matrix enhancing effect in cucumber and cabbage, the others showed matrix inhibitory effect. Conclusion When the method is used to detect the nicotine compounds in vegetables, there are different matrix effects, and matrix type, pesticide molecular structure and matrix concentration all affect the matrix effect intensity. Therefore, the matrix effect must be considered in the actual detection, and it is suggested to use the matrix calibration curve for quantitative analysis.