A simple and rapid method for determination of azinphos-methyl, parathion-methyl and ethoprofos, group of organophosphorus pesticides in wastewater matrices, is presented. A chemometric approach for the optimisation of vortex-assisted dispersive liquid–liquid microextraction experimental conditions prior to liquid chromatography–mass spectrometry detection was applied. In this method, a high-density organic solvent (chloroform) was used as the extractant, with acetone as the disperser solvent. Vortexing was applied prior to centrifugation for phase separation of the organic phase (sedimented layer of extractant) and the aqueous layer. A two-level full factorial design (2⁴) was employed initially for the screening process, and final optimisation of the significant parameters was performed using response surface methodology based on central composite design. The method performance characteristics investigated included linear dynamic range (LDR, 5–100 µg L⁻¹) with a good correlation coefficient (> 0.999). The method precision expressed as intra-day and inter-day relative standard deviation (%RSD) was in the range of 7.8–8.2% and 8.1–9.4%, respectively. The influence of matrix was found to be negligible with recoveries ranging from 99.9 to 106.7%. The proposed method was then applied in real wastewater samples. Extraction recoveries performed at two spiking levels (25 and 100 µg L⁻¹) in untreated (influent) and treated (effluent) wastewater matrices ranged between 94.95 and 119.47%.

中文翻译：

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涡旋辅助分散液液微萃取-液相色谱-质谱法测定废水中的有机磷农药

提出了一种简单而快速的测定废水基质中有机磷农药谷硫磷，甲基对硫磷和乙草磷的方法。在液相色谱-质谱检测之前，采用了一种化学计量学方法来优化涡旋辅助分散液-液微萃取实验条件。在该方法中，使用高密度有机溶剂（氯仿）作为萃取剂，并使用丙酮作为分散剂。在离心之前进行涡旋，以分离有机相（萃取剂的沉淀层）和水层。两级全因子设计（2 ⁴最初用于筛选过程，然后使用基于中心复合设计的响应面方法对重要参数进行最终优化。研究的方法性能特征包括线性动态范围（LDR，5–100 µg L ^-1），具有良好的相关系数（> 0.999）。以日内和日间相对标准偏差（％RSD）表示的方法精度分别在7.8–8.2％和8.1–9.4％的范围内。发现基质的影响可以忽略不计，回收率在99.9％至106.7％之间。然后将所提出的方法应用于实际废水样品中。在两个加标浓度（25和100 µg L ^-1）下进行的提取回收率）在未经处理的（进水）和经过处理的（出水）废水基质中的比率在94.95和119.47％之间。