生活饮用水中麦草畏的检测方法研究及应用
Establishment and application of detection methods of dicamba in drinking water
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摘要:
背景 麦草畏在我国农业生产中被大力推广使用，但其极易溶于水，随饮用水进入体内会对人体健康产生危害，需要建立准确、灵敏、快速的检测方法来测定生活饮用水中该类农药的残留。
目的 建立生活饮用水中麦草畏残留检测的高效液相色谱-串联质谱法和气相色谱-串联质谱法。
方法 采用CAPCELL PAK ST色谱柱、甲酸铵水溶液和甲醇作流动相，等度洗脱，在多反应监测模式下，以电喷雾负离子化模式测定，建立高效液相色谱-串联质谱法；以三甲基硅烷化重氮甲烷作衍生剂，采用外标标准曲线法，建立气相色谱-串联质谱法。用建立的方法，对成都市内6个区域末梢水或二次供水共计7个水样中麦草畏的残留进行检测，探究方法的适用性和了解饮用水中麦草畏的残留现状。
结果 高效液相色谱-串联质谱法检测麦草畏的线性范围为1.00~100 μg·L−1，回归方程为\hat Y =1250.9
X +2681.5，相关系数为0.9988，相对标准偏差在1.23%~26.3%之间，检出限为0.95 μg·L−1，加标回收率在91.8%~111%范围内。气相色谱-串联质谱法检测麦草畏的线性范围为0.200~10.0 μg·L−1，回归方程为\hat Y =190597X +40911，相关系数为0.9993，相对标准偏差在0.64%~3.90%之间，检出限为0.18 μg·L−1，加标回收率在97.3%~105%范围内。对成都市内6个不同地区末梢水或二次供水中麦草畏的残留量进行检测，均未检出麦草畏的存在。结论 本研究建立的两种检测方法具有灵敏、快速的特点，能够满足生活饮用水中麦草畏残留量的检测工作要求，可为后续麦草畏残留检测研究提供实验基础。今后还需对成都市饮用水麦草畏污染持续关注。
Abstract:Background Dicamba is widely used in agricultural production in China, but it is extremely soluble in water and can be harmful to human health when it enters the body via water drinking. It is necessary to establish an accurate, sensitive, and rapid detection method to determine the residues of dicamba in domestic drinking water.
Objective To establish two methods for the determination of dicamba residues in drinking water by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS) respectively.
Methods The conditions of the proposed method using HPLC-MS/MS included CAPCELL PAK ST chromatographic column, ammonium formate water solution and methanol as the mobile phase, and isocratic elution. The system was operated under multiple reaction monitoring mode and electrospray negative ionization mode. Trimethylsilylated diazomethane was used as a derivatizing agent for GC-MS/MS, and an external standard curve was used to evaluate the system. The residues of dicamba in seven water samples of tap water or secondary water supply from six regions in Chengdu were detected by the established systems to evaluate their applicability and to understand the status quo of dicamba residues in drinking water.
Results For the HPLC-MS/MS, the linear range of dicamba was 1.00-100 μg·L−1, the regression equation was \hat Y =1250.9
X +2681.5, the correlation coefficient was 0.9988, the relative standard deviations were 1.23%-26.3%, the limit of detection was 0.95 μg·L−1, and the spiked recoveries were 91.8%-111%. For the GC-MS/MS, the linear range of dicamba was 0.200-10.0 μg·L−1, the regression equation was \hat Y =190597X +40911, the correlation coefficient was 0.9993, the relative standard deviations were 0.64%-3.90%, the limit of detection was 0.18 μg·L−1, and the spiked recoveries were 97.3%-105%. No dicamba residue was identified in the seven water samples of tap water or secondary water supply from six regions in Chengdu by the proposed methods.Conclusion The two detection methods established in this study are sensitive and rapid, meet the requirements from the detection of dicamba residues in drinking water, and provide an experimental basis for subsequent research on the detection of dicamba residues. In the future, it is necessary to continue to pay attention to the pollution of dicamba in drinking water in Chengdu.
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