除草剂在预防和控制杂草和有害植物方面发挥着重要作用,并越来越多地用于农业中,林业,美化环境,和其他领域。然而,除草剂的有效利用率仅为20%-30%,大多数除草剂进入大气,土壤,沉积物,和水环境通过漂移,浸出,和现场应用后的径流。环境中的除草剂残留对生态安全和人类健康构成潜在风险。因此,建立环境样品中除草剂残留的分析方法具有重要意义。在这项研究中,建立了一种基于液相色谱-串联质谱(LC-MS/MS)的正电喷雾电离模式(ESI)的分析方法,甲草胺,以及在土壤中残留的苯磺草胺,沉积物,和水。仪器检测参数,包括电喷雾电离模式,流动相,和色谱柱,进行了优化。流动相为甲醇(A)和0.1%甲酸水溶液(B)。梯度洗脱如下进行:0-1.0分钟,60%A;1.0-2.0min,60%A-90%A;2.0-3.0min,90%A;3.0-4.0min,90%A-60%A;4.0-5.0分钟,60%A.样品用乙腈萃取后加盐,并使用C18固相萃取柱清洗。在样品预处理过程中,研究了不同的固相萃取柱和浸出条件。通过绘制测量的峰面积作为纯溶剂和基质中分析物浓度的函数来构建纯溶剂和基质中的工作曲线。发现了良好的线性,甲草胺,溶剂和基质匹配标准品中的苯磺草胺在0.0005-0.02mg/L范围内,r≥0.9961。三种除草剂在土壤中的基质效应,沉积物,水的比例为-10.1%至16.5%。检测限(LODs,S/N=3),甲草胺,苯磺草胺分别为0.05、0.01和0.02μg/kg,分别。定量限(LOQs,S/N=10),甲草胺,苯磺草胺分别为0.2、0.05和0.05μg/kg,分别。除草剂施用于土壤,沉积物,和浓度为0.005、0.1和2.0mg/kg的水,分别。isoxaflutole的平均回收率,甲草胺,和土壤中的苯磺草胺,沉积物,和水在77.2%-101.9%的范围内,77.9%-105.1%,80.8%-107.1%,分别。isoxaflutole的RSD,甲草胺,苯磺草胺在1.4%-12.8%的范围内,1.2%-7.7%,和1.5%-11.5%,分别。所建立的方法用于分析从浙江省四个不同地点(萧山,台州,东阳,和余杭)和黑龙江(佳木斯)的一个站点。该方法简单,快速,准确,稳定,而且非常实用。它可以用来检测异氧氟沙星,甲草胺,以及在土壤中残留的苯磺草胺,沉积物,为监测除草剂的残留污染和环境行为提供参考。
Herbicides play an important role in preventing and controlling weeds and harmful plants and are increasingly used in agriculture, forestry, landscaping, and other fields. However, the effective utilization rate of herbicides is only 20%-30%, and most herbicides enter the atmosphere, soil, sediment, and water environments through drift, leaching, and runoff after field application. Herbicide residues in the environment pose potential risks to ecological safety and human health. Therefore, establishing analytical methods to determine herbicide residues in environmental samples is of great importance. In this study, an analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization mode (ESI+) was developed for the determination of isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water. The instrumental detection parameters, including electrospray ionization mode, mobile phase, and chromatographic column, were optimized. The mobile phases were methanol (A) and 0.1% formic acid aqueous solution (B). Gradient elution was performed as follows: 0-1.0 min, 60%A; 1.0-2.0 min, 60%A-90%A; 2.0-3.0 min, 90%A; 3.0-4.0 min, 90%A-60%A; 4.0-5.0 min, 60%A. The samples were salted after extraction with acetonitrile and cleaned using a C18 solid-phase extraction column. Different solid-phase extraction columns and leaching conditions were investigated during sample pretreatment. Working curves in the neat solvent and matrix were constructed by plotting the measured peak areas as a function of the concentrations of the analytes in the neat solvent and matrix. Good linearities were found for isoxaflutole, metazachlor, and saflufenacil in the solvent and matrix-matched standards in the range of 0.0005-0.02 mg/L, with r≥0.9961. The matrix effects of the three herbicides in soil, sediment, and water ranged from -10.1% to 16.5%. The limits of detection (LODs, S/N=3) for isoxaflutole, metazachlor, and saflufenacil were 0.05, 0.01, and 0.02 μg/kg, respectively. The limits of quantification (LOQs, S/N=10) for isoxaflutole, metazachlor, and saflufenacil were 0.2, 0.05, and 0.05 μg/kg, respectively. The herbicides were applied to soil, sediment, and water at spiked levels of 0.005, 0.1, and 2.0 mg/kg, respectively. The average recoveries for isoxaflutole, metazachlor, and saflufenacil in soil, sediment, and water were in the ranges of 77.2%-101.9%, 77.9%-105.1%, and 80.8%-107.1%, respectively. The RSDs for isoxaflutole, metazachlor, and saflufenacil were in the ranges of 1.4%-12.8%, 1.2%-7.7%, and 1.5%-11.5%, respectively. The established method was used to analyze actual samples collected from four different sites in Zhejiang Province (Xiaoshan, Taizhou, Dongyang, and Yuhang) and one site in Heilongjiang (Jiamusi). The proposed method is simple, rapid, accurate, stable, and highly practical. It can be used to detect isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water and provides a reference for monitoring the residual pollution and environmental behavior of herbicides.