title: Multiresidue pesticide analysis of agricultural commodities using acetonitrile salt-out extraction, dispersive solid-phase sample clean-up, and high-performance liquid chromatography-tandem mass spectrometry.
abstract: A multiresidue method analyzing 209 pesticides in 24 agricultural commodities has been developed and validated using the original Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) procedure and high performance liquid chromatography-positive electrospray ionization-tandem mass spectrometry (LC-MS/MS) analysis. Using solvent-only calibration standards (SOCSs) and matrix-matched calibration standards (MMCSs), it was demonstrated that a minimal concentration of 5-10 μg/kg (part per billion, ppb) of analytes in matrix is required for the consistent identification of targeted pesticides with two MRM transitions. Method performance was validated by the precision and accuracy results obtained from fortification studies at 10, 25, 100, and 500 ppb and MMCSs. The method was demonstrated to achieve an average recovery of 100 ± 20% (n = 4) for >75% of evaluated pesticides at the low fortification level (10 ppb) and improved to >84% at the higher fortification concentrations in all 24 matrices. Matrix effects in LC-MS/MS analysis were studied by evaluating the slope ratios of calibration curves (1.0-100 ng/mL) obtained from the SOCSs and MMCSs. Principal component analysis (PCA) of LC-MS/MS and method validation data confirmed that each matrix exerts its specific effect during the sample preparation and LC-MS/MS analysis. The matrix effect is primarily dependent on the matrix type, pesticide type and concentration. Some caution is warranted when using matrix matched calibration curves for the quantitation of pesticides to alleviate concerns on matrix effects. The QuEChERS method with LC-MS/MS was used to identify and quantitate pesticides residues, with concentrations ranging from 2.5 to >1000 ppb in a variety of agricultural samples, demonstrating fitness for screening and surveillance applications.
authors.affiliation: U.S. Food and Drug Administration , Center for Food Safety and Applied Nutrition, College Park, MD 20740-3835, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Jon W
authors.initials: JW
authors.lastname: Wong
authors.forename: Paul
authors.initials: P
authors.lastname: Yang
authors.forename: Katherine
authors.initials: K
authors.lastname: Tech
authors.forename: Alex L
authors.initials: AL
authors.lastname: Dibenedetto
authors.forename: Nathaniel S
authors.initials: NS
authors.lastname: Lee
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Hayward
authors.forename: Carolyn M
authors.initials: CM
authors.lastname: Makovi
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Krynitsky
authors.forename: Kaushik
authors.initials: K
authors.lastname: Banerjee
authors.forename: Lillian
authors.initials: L
authors.lastname: Jao
authors.forename: Soma
authors.initials: S
authors.lastname: Dasgupta
authors.forename: Michael S
authors.initials: MS
authors.lastname: Smoker
authors.forename: Roger
authors.initials: R
authors.lastname: Simonds
authors.forename: Andre
authors.initials: A
authors.lastname: Schreiber
mesh_terms: D000097:Acetonitriles; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D018556:Crops, Agricultural / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014675:Vegetables / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D010573:Pesticide Residues; C032159:acetonitrile