title: Ultrapreconcentration and determination of organophosphorus pesticides in water by solid-phase extraction combined with dispersive liquid-liquid microextraction and high-performance liquid chromatography.
abstract: Solid-phase extraction coupled with dispersive liquid-liquid microextraction was developed as an ultra-preconcentration method for the determination of four organophosphorus pesticides (isocarbophos, parathion-methyl, triazophos and fenitrothion) in water samples. The analytes considered in this study were rapidly extracted and concentrated from large volumes of aqueous solutions (100 mL) by solid-phase extraction coupled with dispersive liquid-liquid microextraction and then analyzed using high performance liquid chromatography. Experimental variables including type and volume of elution solvent, volume and flow rate of sample solution, salt concentration, type and volume of extraction solvent and sample solution pH were investigated for the solid-phase extraction coupled with dispersive liquid-liquid microextraction with these analytes, and the best results were obtained using methanol as eluent and ethylene chloride as extraction solvent. Under the optimal conditions, an exhaustive extraction for four analytes (recoveries >86.9%) and high enrichment factors were attained. The limits of detection were between 0.021 and 0.15 μg/L. The relative standard deviations for 0.5 μg/L of the pesticides in water were in the range of 1.9-6.8% (n = 5). The proposed strategy offered the advantages of simple operation, high enrichment factor and sensitivity and was successfully applied to the determination of four organophosphorus pesticides in water samples.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China.
authors.forename: Junhua
authors.initials: J
authors.lastname: Chen
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China.
authors.forename: Yongli
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shen
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Chongqing University, Chongqing, China.
authors.forename: Guilong
authors.initials: G
authors.lastname: Peng
keywords: Dispersive liquid-liquid microextraction; High-performance liquid chromatography; Organophosphorus pesticides; Solid-phase extraction