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Comparison of two ionic liquid dispersive liquid–liquid microextraction approaches for the determination of benzoylurea insecticides in wastewater using liquid chromatography–quadrupole-linear ion trap–mass spectrometry: Evaluation of green parameters A

Vázquez, M.M. Parrilla, Vázquez, P. Parrilla, Galera, M. Martínez, Moreno, A. Uclés
Journal of chromatography 2014 v.1356 pp. 1-9
agricultural zoning, detection limit, diflubenzuron, ecotoxicology, flufenoxuron, hexaflumuron, high performance liquid chromatography, insecticide residues, insecticides, ionic liquids, liquid-phase microextraction, lufenuron, mass spectrometry, methanol, spectrometers, statistical analysis, teflubenzuron, triflumuron, ultrasonic treatment, wastewater, wastewater treatment, Spain
Two dispersive liquid–liquid microextraction (DLLME) approaches including temperature-controlled ionic liquid dispersive liquid–liquid microextraction (TCIL-DLLME) and ultrasound-assisted ionic liquid dispersive liquid–liquid microextraction (US-IL-DLLME) were compared for the extraction of six benzoylurea insecticides (diflubenzuron, triflumuron, hexaflumuron, teflubenzuron, lufenuron and flufenoxuron) from wastewater samples prior to their determination by high-performance liquid chromatography with a hybrid triple quadrupole-linear ion trap–mass spectrometer (LC–QqLIT–MS/MS). Influential parameters affecting extraction efficiency were systematically studied and optimized and the most significant green parameters were quantified and compared. The best results were obtained using the US-IL-DLLME procedure, which employed the IL 1-octyl-3-methylimidazolium hexafluorophosphate ([C8MIM][PF6]) and methanol (MeOH) as extraction and disperser solvent, respectively. US-IL-DLLME procedure was fast, easy, low environmental toxicity and, it was also able to successfully extract all selected benzoylureas. This method was extensively validated with satisfactory results: limits of detection and quantification were in the range 0.5–1.0ngL⁻¹ and 1.5–3.5ngL⁻¹, respectively, whereas recovery rates ranged from 89 to 103% and the relative standard deviations were lower than 13.4%. The applicability of the method was assessed with the analysis of effluent wastewater samples from a wastewater treatment plant located in an agricultural zone of Almería (Spain) and the results indicated the presence of teflubenzuron at mean concentration levels of 11.3ngL⁻¹. US-IL-DLLME sample treatment in combination with LC–QqLIT–MS/MS has demonstrated to be a sensitive, selective and efficient method to determine benzoylurea insecticides in wastewaters at ultra-trace levels.