Donato Filipe F, Bandeira Nelson M G, Dos Santos Gabriel C, Prestes Osmar D, Adaime Martha B, Zanella Renato
Laboratory of Pesticide Residue Analysis (LARP), Chemistry Department, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
Laboratory of Pesticide Residue Analysis (LARP), Chemistry Department, Federal University of Santa Maria, 97105-900 Santa Maria, RS, Brazil.
J Chromatogr A. 2017 Sep 22;1516:54-63. doi: 10.1016/j.chroma.2017.08.025. Epub 2017 Aug 12.
The use of pesticides has been associated with the increase of productivity of crops and control of vectors that cause diseases. However, excessive use of these compounds can cause human health and environmental problems, especially regarding to water resources. In this work, a method for multiresidue determination of 62 pesticides in surface water using the rotating disk sorptive extraction (RDSE) technique for sample preparation and ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) for analysis was optimized and validated. The parameters time and rotational disk velocity for the extraction step, types and amounts of sorbents, sample pH, ionic strength, time and velocity of the rotating disk in the desorption step, as well different desorption solvents were evaluated. The best results were obtained using 50mL of sample, acidified at pH 2.0, and 2.5g of sodium chloride. The selected velocity of rotation in the extraction step was 1600rpm for 80min. Inside the disk cavity, a small amount (20mg) of the polymeric sorbent Oasis HLB was used. The desorption step was performed immerging the disk in 3mL of methanol and rotating the disk at 1600rpm for 60min. Procedural calibration curves showed linearity between 0.05 or 0.1-2μgL, with r>0.99 for all compounds. The method presented practical limit of quantification of 0.05 or 0.1μgL and suitable accuracy and precision, with recoveries from 70.1 to 119.9% and RSD≤20% for the levels 0.05, 0.1, 0.5 and 2μgL. The validated method was applied to surface water samples from different river and residues of atrazine, azoxystrobin, clomazone, difenoconazole, epoxiconazole, propoxur, simazine and tebuconazole were found in the range of 0.06-0.35μgL. The results indicate that the proposed method is suitable for the determination of pesticide residues in surface water, allowing an easy and simultaneously preparation of several samples with low material consumption.
农药的使用与农作物产量的提高以及对致病媒介的控制有关。然而，过度使用这些化合物会导致人类健康和环境问题，尤其是在水资源方面。在这项工作中，优化并验证了一种使用旋转盘吸附萃取（RDSE）技术进行样品前处理、超高效液相色谱-串联质谱（UHPLC-MS/MS）进行分析的地表水中62种农药多残留测定方法。对萃取步骤的时间和旋转盘速度、吸附剂的类型和用量、样品pH值、离子强度、解吸步骤中旋转盘的时间和速度以及不同的解吸溶剂进行了评估。使用50mL pH值为2.0的酸化样品和2.5g氯化钠可获得最佳结果。萃取步骤中选定的旋转速度为1600rpm，持续80分钟。在盘腔内，使用少量（20mg）的聚合物吸附剂Oasis HLB。解吸步骤是将盘浸入3mL甲醇中，并以1600rpm旋转盘60分钟。程序校准曲线在0.05或0.1 - 2μg/L之间呈线性，所有化合物的r>0.99。该方法的实际定量限为0.05或0.1μg/L，具有合适的准确度和精密度，对于0.05、0.1、0.5和2μg/L的水平，回收率为70.1%至119.9%，相对标准偏差（RSD）≤20%。经过验证的方法应用于不同河流的地表水样品，发现阿特拉津、嘧菌酯、异噁草酮、苯醚甲环唑、环氧唑、残杀威、西玛津和戊唑醇的残留量在0.06 - 0.35μg/L范围内。结果表明，所提出的方法适用于地表水中农药残留的测定，能够轻松且同时制备多个样品，材料消耗低。
