title: Multiresidue analysis of pesticides in fruits and vegetables using disposable pipette extraction (DPX) and micro-luke method.
abstract: Simple and rapid methods for the analysis of pesticides in produce samples have been developed. The current study involves analysis of nonpolar and polar pesticides using GC-ECD and GC-NPD, respectively. The nonpolar pesticides were extracted using disposable pipette extraction (DPX) following a preliminary acetone extraction based on the Luke method. Recoveries of the fortified pesticides ranged between 70.5 and 110.0%, with relative standard deviations (% RSD) below 10% for most target analytes. From calibration plots, the limits of detection (LOD) were determined to be <0.05 ppm for most studied pesticides with coefficients of determination (r(2)) >0.99. A micro-Luke method was adapted and used for the analysis of polar pesticides, which greatly reduces the volumes of solvent and time for sample preparation. This new method of analysis, combining DPX and micro-Luke, was compared directly with the modified Luke method for analysis of pesticides in produce samples over a 9 week period. This study validates the suitability for routine analysis of pesticides in acetone extract of fruits and vegetables using the proposed DPX and micro-Luke method.
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: Sherry T
authors.initials: ST
authors.lastname: Garris
authors.forename: Chanin
authors.initials: C
authors.lastname: Craft
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Morgan
mesh_terms: D000096:Acetone; D005591:Chemical Fractionation / Q000295:instrumentation* / Q000379:methods*; D002849:Chromatography, Gas / Q000379:methods; D004209:Disposable Equipment; D005638:Fruit / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry; D011786:Quality Control; D015203:Reproducibility of Results; D014675:Vegetables / Q000737:chemistry*
chemical_list: D010573:Pesticide Residues; D010936:Plant Extracts; D000096:Acetone