title: Vortex-assisted low density solvent based demulsified dispersive liquid-liquid microextraction and high-performance liquid chromatography for the determination of organophosphorus pesticides in water samples.
abstract: A simple, rapid, effective and eco-friendly preconcentration method, vortex-assisted low density solvent based solvent demulsified dispersive liquid-liquid microextraction (VLDS-SD-DLLME), followed by high performance liquid chromatography-diode array detector (HPLC-DAD) analysis, has been developed for the first time for the determination of four organophosphorus pesticides (OPPs) (e.g., azinphos-methyl, parathion-methyl, fenitrothion and diazinon) in environmental water samples. In this preconcentration procedure, an emulsion was obtained after the mixture of extraction solvent (1-dodecanol) and dispersive solvent (acetonitrile, ACN) was injected rapidly into 10 mL of the sample solution. The vortex agitator aided the dispersion of the extraction solvent into the sample solution. After the formation of an emulsion, the demulsifier (ACN) was added, resulting in the rapid separation of the mixture into two phases without centrifugation. Under optimal conditions, the proposed method provided high extraction efficiency (90-99%), good linearity range (0.5-500 ng mL(-1)), low limits of detection (0.25-1 ng mL(-1)) and good repeatability and recoveries were obtained.
authors: Materials Chemistry Research Unit, Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
authors: Ketsarin
authors: K
authors: Seebunrueng
authors: Department of Chemistry, Faculty of Engineering, Rajamangala University of Technology Isan, Khon Kaen Campus, Khon Kaen 40000, Thailand.
authors: Yanawath
authors: Y
authors: Santaladchaiyakit
authors: Materials Chemistry Research Unit, Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: supalax@kku.ac.th.
authors: Supalax
authors: S
authors: Srijaranai
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007851:Dodecanol / Q000737:chemistry; D004655:Emulsions; D057230:Limit of Detection; D059627:Liquid Phase Microextraction; D009943:Organophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D012997:Solvents / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004655:Emulsions; D009943:Organophosphorus Compounds; D010575:Pesticides; D012997:Solvents; D014874:Water Pollutants, Chemical; D007851:Dodecanol
keywords: Demulsified dispersive liquid–liquid microextraction; Environmental water sample; High performance liquid chromatography; Low-density solvent; Organophosphorus pesticides; Vortex-assisted extraction