title: Development of dispersive liquid-liquid microextraction method for the analysis of organophosphorus pesticides in tea.
abstract: In this article, a new method for the determination of organophosphorus pesticides (OPPs) in tea was developed by using dispersive liquid-liquid microextraction (DLLME) and gas chromatography-flame photometric detection (GC-FPD). A mixture of acetonitrile and n-hexane was used as an extraction solvent for the extraction of OPPs from tea samples. When the extraction process was finished, the mixture of solvents was rapidly dispersed in water; target analyte was extracted to a small volume of n-hexane, using DLLME. Recovery tests were performed for concentration 5.0 microg/kg. The recovery for each target analyte was in the range between 83.3 and 117.4%. The repeatability of the proposed method, expressed as relative standard deviation, varied between 3 and 7.8% (n=3). The detection limit of the method for tea was found ranging from 0.030 to 1 microg/kg for all the target pesticides. Compared with the conventional sample preparation method, the proposed method has the advantage of being quick and easy to operate, and has high-enrichment factors and low consumption of organic solvent.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Iran University of Science and Technology, Tehran, Iran.
authors.forename: Soleyman
authors.initials: S
authors.lastname: Moinfar
authors.forename: Mohammad-Reza Milani
authors.initials: MR
authors.lastname: Hosseini
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D002849:Chromatography, Gas; D005506:Food Contamination / Q000032:analysis; D009943:Organophosphorus Compounds / Q000032:analysis / Q000302:isolation & purification; D010575:Pesticides / Q000032:analysis* / Q000302:isolation & purification; D012997:Solvents; D013662:Tea / Q000737:chemistry*
chemical_list: D009943:Organophosphorus Compounds; D010575:Pesticides; D012997:Solvents; D013662:Tea