title: Homogeneous Liquid-Liquid Microextraction for Determination of Organophosphorus Pesticides in Environmental Water Samples Prior to Gas Chromatography-Flame Photometric Detection.
abstract: In this study, homogeneous liquid-liquid microextraction (HLLME) was developed for preconcentration and extraction of 15 organophosphorus pesticides (OPPs) from water samples coupling with gas chromatography followed by a flame photometric detector (HLLME-GC-FPD). In this method, OPPs were extracted by the homogeneous phase in a ternary solvent system (water/acetic acid/chloroform). The homogeneous solution was excluded by the addition of sodium hydroxide as a phase separator reagent and a cloudy solution was formed. After centrifugation (3 min at 5,000 rpm), the fine particles of extraction solvent (chloroform) were sedimented at the bottom of the conical test tube (10.0 ± 0.5 µL). Furthermore, 0.5 µL of the sedimented phase was injected into the GC for separation and determination of OPPs. Optimal results were obtained under the following conditions: volume of the extracting solvent (chloroform), 53 µL; volume of the consolute solvent (acetic acid), 0.76 mL and concentration of sodium hydroxide, 40% (w/v). Under the optimum conditions, the enrichment factors of (260-665), the extraction percent of 75.8-104%, the dynamic linear range of 0.03-300 µg L(-1) and the limits of detection of 0.004-0.03 µg L(-1) were obtained for the OPPs. This method was successfully applied for the extraction and determination of the OPPs in environmental water samples.
authors.affiliation: Department of Applied Chemistry, Faculty of Science, Islamic Azad University, South Tehran Branch, Tehran, Iran berijani@gmail.com.
authors.forename: Sana
authors.initials: S
authors.lastname: Berijani
authors.affiliation: Department of Civil Engineering, University of Science and Culture, Tehran, Iran.
authors.forename: Mirhanif
authors.initials: M
authors.lastname: Sadigh
authors.affiliation: Department of Chemistry, College of Science, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Pournamdari
mesh_terms: D002849:Chromatography, Gas; D004784:Environmental Monitoring / Q000379:methods*; D059627:Liquid Phase Microextraction; D010575:Pesticides / Q000032:analysis*; D015203:Reproducibility of Results; D012997:Solvents; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D010575:Pesticides; D012997:Solvents; D014874:Water Pollutants, Chemical; D014867:Water