title: New approach to multiresidue pesticide determination in foods with high fat content using disposable pipette extraction (DPX) and gas chromatography-mass spectrometry (GC-MS).
abstract: Organochlorine and organophosphate pesticides in corn muffin mix and cocoa beans were analyzed using disposable pipette extraction (DPX) for rapid cleanup followed by gas chromatography-mass spectrometry (GC-MS). The DPX method in this study used weak anion exchange (WAX) mechanisms to remove the major sample matrix interferences, fatty acids, from the chromatographic analyses. The limits of detection (LOD) were determined to be <10 ppb for all studied pesticides in corn muffin. DPX-WAX exhibited average recoveries reaching 100% for most targeted pesticides, with relative standard deviations below 10%. These results indicate that DPX with weak anion exchange sorbent is effective at eliminating fatty acid interferences in foods of high fat content prior to multiresidue pesticide analysis. Furthermore, the DPX cleanup method takes approximately 2 min to perform. In addition, removal of fatty acids from cocoa beans demonstrates the high capacity of this extraction method for samples containing up to 50% fat.
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, USA.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Guan
authors.forename: William E
authors.initials: WE
authors.lastname: Brewer
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Morgan
mesh_terms: D000097:Acetonitriles; D000327:Adsorption; D000837:Anion Exchange Resins; D002099:Cacao / Q000737:chemistry; D004041:Dietary Fats / Q000032:analysis*; D004209:Disposable Equipment; D005227:Fatty Acids / Q000302:isolation & purification; D005504:Food Analysis / Q000295:instrumentation* / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis; D010755:Organophosphates / Q000032:analysis; D010573:Pesticide Residues / Q000032:analysis*; D015203:Reproducibility of Results; D012639:Seeds / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D000837:Anion Exchange Resins; D004041:Dietary Fats; D005227:Fatty Acids; D006843:Hydrocarbons, Chlorinated; D010755:Organophosphates; D010573:Pesticide Residues; C032159:acetonitrile