title: Chemometric assisted ultrasound leaching-solid phase extraction followed by dispersive-solidification liquid-liquid microextraction for determination of organophosphorus pesticides in soil samples.
abstract: Ultrasound leaching-solid phase extraction (USL-SPE) followed by dispersive-solidification liquid-liquid microextraction (DSLLME) was developed for preconcentration and determination of organophosphorus pesticides (OPPs) in soil samples prior gas chromatography-mass spectrometry analysis. At first, OPPs were ultrasonically leached from soil samples by using methanol. After centrifugation, the separated methanol was diluted to 50 mL with double-distillated water and passed through the C18 SPE cartridge. OPPs were eluted with 1 mL acetonitrile. Thus, 1 mL acetonitrile extract (disperser solvent) and 10 µL 1-undecanol (extraction solvent) were added to 5 mL double-distilled water and a DSLLME technique was applied. The variables of interest in the USL-SPE-DSLLME method were optimized with the aid of chemometric approaches. First, in screening experiments, fractional factorial design (FFD) was used for selecting the variables which significantly affected the extraction procedure. Afterwards, the significant variables were optimized using response surface methodology (RSM) based on central composite design (CCD). Under the optimum conditions, the enrichment factors were 6890-8830. The linear range was 0.025-625 ng g(-1) and limits of detection (LODs) were between 0.012 and 0.2 ng g(-1). The relative standard deviations (RSDs) were in the range of 4.06-8.9% (n=6). The relative recoveries of OPPs from different soil samples were 85-98%.
authors.affiliation: Department of Petroleum Engineering, Faculty of Engineering, South Tehran Branch, Islamic Azad University, P.O. Box 11365-4435, Tehran, Iran.
authors.forename: Kamyar
authors.initials: K
authors.lastname: Ahmadi
authors.affiliation: Arian Tajhiz Azma Company, Tehran, Iran.
authors.forename: Yaser
authors.initials: Y
authors.lastname: Abdollahzadeh
authors.affiliation: Department of Petroleum Engineering, Faculty of Engineering, South Tehran Branch, Islamic Azad University, P.O. Box 11365-4435, Tehran, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Asadollahzadeh
authors.affiliation: Department of Petroleum Engineering, Faculty of Engineering, South Tehran Branch, Islamic Azad University, P.O. Box 11365-4435, Tehran, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Hemmati
authors.affiliation: The Young Research Club of the Islamic Azad University, Nour Branch, Nour, Iran. Electronic address: ha.tavakoli159@yahoo.com.
authors.forename: Hamed
authors.initials: H
authors.lastname: Tavakoli
authors.affiliation: University College of Engineering, University of Tehran, Enghelab Ave., Tehran, Iran.
authors.forename: Rezvan
authors.initials: R
authors.lastname: Torkaman
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D059627:Liquid Phase Microextraction / Q000379:methods*; D008962:Models, Theoretical; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000302:isolation & purification*; D010575:Pesticides / Q000032:analysis / Q000302:isolation & purification; D012987:Soil / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D012997:Solvents / Q000737:chemistry; D000069453:Ultrasonic Waves; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification
chemical_list: D009943:Organophosphorus Compounds; D010575:Pesticides; D012987:Soil; D012997:Solvents; D014874:Water Pollutants, Chemical
keywords: Chemometric tools; Dispersive-solidification liquid–liquid microextraction; Organophosphorus pesticides; Soil samples; Solid phase extraction