Assessment of a Fully Optimized DPX-Based Procedure for the Multiclass Determination of Pesticides in Drinking Water Using High-Performance Liquid Chromatography with Diode Array Detection

In this study, a disposable pipette extraction (DPX)-based procedure was fully optimized for the multiclass determination of 12 pesticides, with significant differences in their physicochemical properties, using high-performance liquid chromatography coupled with diode array detection (HPLC-DAD). The variables optimized were type of extraction phase, sample pH, sample volume, number of extraction and desorption cycles, time of each cycle, type and volume of desorption solvent, and NaCl concentration of the samples. The analytical parameters of merit were determined under optimized conditions and satisfactory results were achieved, with limits of detection (LOQs) varying from 0.06 µg L-1 for carbofuran to 2.30 µg L-1 for carbendazim and correlation coefficients of 0.9923 to 0.9999. Relative recoveries ranged from 75 to 117%. Good results were achieved for intraday (n = 3) precision (1 to 20%) and interday (n = 9) precision (1 to 24%). The method was applied to the monitoring of 20 drinking water samples collected from water treatment plants.

本研究针对12种理化性质差异显著的农药，采用高效液相色谱-二极管阵列检测法（high-performance liquid chromatography coupled with diode array detection, HPLC-DAD），对基于一次性移液管萃取（disposable pipette extraction, DPX）的前处理流程进行了全面优化，以实现多类农药的同时定量测定。本次优化的变量包括萃取相类型、样品pH值、样品体积、萃取与解吸循环次数、单次循环时长、解吸溶剂的类型与体积，以及样品的氯化钠浓度。在优化条件下测定了该方法的分析性能指标，最终取得了令人满意的结果：检出限（limits of detection, LOQs）范围为克百威（carbofuran）的0.06 μg·L⁻¹至多菌灵（carbendazim）的2.30 μg·L⁻¹，相关系数介于0.9923至0.9999之间；相对回收率介于75%至117%。日内（n=3）与日间（n=9）精密度均表现良好，其相对标准偏差分别为1%至20%与1%至24%。将该方法应用于20份取自自来水厂的饮用水样品的监测分析。