DETERMINATION OF THE PESTICIDES IN WATER USED IN THE CULTURE AND PROCESSING OF POTATOES

The contamination of water bodies by pesticide residues through direct flow, leaching and other methods has motivated the development of analytical methods for the determination of these compounds in water. A vortex-assisted liquid-liquid microextraction method followed by gas chromatography coupled to mass spectrometry for the determination of anilazine, linuron, prothiofos, and tebuconazole residues in water samples from the culture and processing of potatoes (Solanum tuberosum L.) was optimized. The complete factorial design and the central rotational compound design combined with the desirability function were used to evaluate and optimize the parameters of the method. The optimized conditions for extracting the pesticides were as follows: 316 µL of toluene, no sodium chloride addition, and a stirring time of 187 s. The method presented an enrichment factor of 142.4 times and good linearity, precision and accuracy, with limits of detection (LOD) of 0.005 - 0.007 mg L-1 and limits of quantification (LOQ) of 0.016 - 0.022 mg L-1. The co-extractives of the wastewater samples caused the suppression of the chromatographic response of linuron and prothiofos by 7.82 and 27.63%, respectively. The analyte concentrations in the wastewater samples from the industrial shing process, manual potato washing, and dam water were either lower than the LODs of the method or were absent.

农药残留通过径流、淋溶等途径污染水体，推动了水体中该类化合物检测分析方法的研发。针对马铃薯（Solanum tuberosum L.）种植与加工环节的水样，本研究优化了一种结合涡旋辅助液液微萃取（vortex-assisted liquid-liquid microextraction）与气相色谱-质谱联用法（gas chromatography coupled to mass spectrometry）的分析方法，用于测定其中敌菌灵、利谷隆、丙硫磷及戊唑醇残留。本研究采用全因子设计（complete factorial design）与中心复合旋转设计（central rotational compound design）结合期望函数法（desirability function），对该方法的参数进行评价与优化。该农药萃取的最优条件为：甲苯用量316 μL，不添加氯化钠，搅拌时长187 s。该方法的富集因子可达142.4倍，且具备良好的线性、精密度与准确度，检出限（LOD, limits of detection）为0.005~0.007 mg·L⁻¹，定量限（LOQ, limits of quantification）为0.016~0.022 mg·L⁻¹。废水样品中的共萃取物会使利谷隆与丙硫磷的色谱响应分别降低7.82%和27.63%。工业清洗工序、马铃薯手工清洗环节以及坝塘水样中的待测物浓度均低于本方法的检出限，或未被检出。