Application of ultrasound-assisted surfactant-enhanced emulsification microextraction for the determination of some organophosphorus pesticides in water samples.
An ultrasound-assisted surfactant-enhanced emulsification microextraction (UASEME) was developed as a new approach for the extraction of organophosphorus pesticides (OPs) in water samples prior to high-performance liquid chromatography with diode array detection (HPLC-DAD). The use of a surfactant as an emulsifier in the UASEME method could enhance the dispersion of water-immiscible extraction solvent into aqueous phase and is favorable for the mass-transfer of the analytes from aqueous phase to the organic phase. Several variables that affect the extraction efficiency, including the kind and volume of the extraction solvent, the type and concentration of the surfactant, salt addition, ultrasound emulsification time and temperature, were investigated and optimized. Under the optimum experimental conditions, the calibration curve was linear in the concentration range from 1 to 200 ng mL(-1) for the seven OPs (isocarbophos, phosmet, parathion, parathion-methyl, fenitrothion, fonofos and phoxim), with the correlation coefficients (r) varying from 0.9973 to 0.9998. High enrichment factors were achieved ranging from 210 to 242. The established UASEME-HPLC-DAD method has been successfully applied for the determination of the OPs in real water samples. The limits of detection were in the range between 0.1 and 0.3 ng mL(-1). The recoveries of the target analytes over the three spiked concentration levels of the compounds (10, 50, and 100 ng mL(-1), respectively) in rain, reservoir and well water samples were between 83% and 106% with the relative standard deviations varying from 3.3% to 5.6%.
Wu
Chunxia
C
Key Laboratory of Bioinorganic Chemistry, College of Science, Agricultural University of Hebei, Baoding 071001, Hebei, China.
Liu
Ning
N
Wu
Qiuhua
Q
Wang
Chun
C
Wang
Zhi
Z
D053000:Analytic Sample Preparation Methods; D005591:Chemical Fractionation / Q000379:methods*; D002725:Chloroform / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004655:Emulsions / Q000737:chemistry; D005618:Fresh Water / Q000737:chemistry*; D057230:Limit of Detection; D016014:Linear Models; D009946:Organothiophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D015203:Reproducibility of Results; D012965:Sodium Chloride / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D014465:Ultrasonics
D004655:Emulsions; D009946:Organothiophosphorus Compounds; D010575:Pesticides; D013501:Surface-Active Agents; D012965:Sodium Chloride; D002725:Chloroform