title: Determination of organophosphorus pesticides by gas chromatography with mass spectrometry using a large-volume injection technique after magnetic extraction.
abstract: A fast and efficient method was developed for the extraction and determination of organophosphorus pesticides in water samples. Organophosphorus pesticides were extracted by solid-phase extraction using magnetic multi-walled carbon nanotubes and determined by gas chromatography with ion-trap mass spectrometry. Parameters affecting the extraction were investigated. Under optimum conditions of the method, 10 mg magnetic multi-walled carbon nanotubes were added into 10 mL sample. After 2 min, adsorbent particles settled at the bottom of test tube with a magnet. After removing aqueous supernatant, the analytes were desorbed with acetonitrile. Then, 70 μL of acetonitrile phase was injected into the gas chromatography and mass spectrometry system that had an ion-trap analyzer. To achieve high sensitivity, the large-volume-injection technique was used with a programmed temperature vaporization inlet, and the ion-trap mass spectrometer was operated in single ion storage mode. Under the best conditions, the enrichment factors and extraction recoveries were in the range of 113-124 and 74-103%, respectively. The limits of detection were between 3 and 15 ng/L, and the relative standard deviations were < 10%. This method was successfully used for the determination of organophosphorus pesticides in dam water, lagoon water, and river water samples with good reproducibility and recovery.
authors: Department of chemistry, Payame Noor University, Tehran, Iran.
authors: Maryam
authors: M
authors: Nedaei
authors: Ali-Reza
authors: AR
authors: Salehpour
authors: Shahla
authors: S
authors: Mozaffari
authors: Seyedeh Mahboobeh
authors: SM
authors: Yousefi
authors: Seyed Reza
authors: SR
authors: Yousefi
mesh_terms: D005618:Fresh Water / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009943:Organophosphorus Compounds / Q000032:analysis* / Q000302:isolation & purification; D010575:Pesticides / Q000032:analysis* / Q000302:isolation & purification*; D045483:Rivers / Q000737:chemistry; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification*
chemical_list: D009943:Organophosphorus Compounds; D010575:Pesticides; D014874:Water Pollutants, Chemical
keywords: Large volume injection; Magnetic multiwalled carbon nanotubes; Organophosphorus pesticides