title: Sample preparation method for the analysis of some organophosphorus pesticides residues in tomato by ultrasound-assisted solvent extraction followed by dispersive liquid-liquid microextraction.
abstract: A very simple and economic method for organophosphorus pesticides (OPPs) residues analysis in tomato by means of gas chromatography-flame photometric detection (GC-FPD) has been developed. The method involves a rapid and small-scale extraction. The sample was homogenised and extraction of the OPPs with acetone was carried out assisted by sonication. No clean-up or evaporation were required after extraction. Pre-concentration of the OPPs from the acetone extract was done by using dispersive liquid-liquid microextraction (DLLME) technique. Chlorobenzene was added in micro-level volume as extraction solvent and triphenylphosphate as internal standard in DLLME procedure. The method showed good linearity over the range assayed (0.5-1000μgkg(-1)) and the detection limits for the pesticides studied varied from 0.1 to 0.5μgkg(-1). Repeatability studies resulted a relative standard deviation lower than 10% in all cases. The proposed method was used to determine pesticides levels in tomatoes grown in open field.
authors.affiliation: Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
authors.forename: Araz
authors.initials: A
authors.lastname: Bidari
authors.affiliation: Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ganjali
authors.affiliation: Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
authors.forename: Parviz
authors.initials: P
authors.lastname: Norouzi
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Iran University of Science and Technology, P.O. Box 16846-13114, Tehran, Iran; Electroanalytical Chemistry Research Center, Iran University of Science and Technology, P.O. Box 16846-13114, Tehran, Iran.
authors.forename: Mohammad Reza Milani
authors.initials: MR
authors.lastname: Hosseini
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Iran University of Science and Technology, P.O. Box 16846-13114, Tehran, Iran; Electroanalytical Chemistry Research Center, Iran University of Science and Technology, P.O. Box 16846-13114, Tehran, Iran. Electronic address: y_assadi@iust.ac.ir.
authors.forename: Yaghoub
authors.initials: Y
authors.lastname: Assadi
keywords: Dispersive liquid–liquid microextraction; Gas chromatography-flame photometric detection; Organophosphorus pesticides; Sample preparation; Tomato; Ultrasound-assisted solvent extraction