title: Development and interlaboratory validation of a QuEChERS-based liquid chromatography-tandem mass spectrometry method for multiresidue pesticide analysis.
abstract: A high-throughput, QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) sample preparation and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method has been developed and validated for the determination of 191 pesticides in vegetation and fruit samples. Using identical LC analytical column and MS/MS instrumentation and operation parameters, this method was evaluated at the U.S. Food and Drug Administration (FDA), National Research Centre for Grapes (NRCG), India, and Ontario Ministry of the Environment (MOE) laboratories. Method validation results showed that all but 1 of these 191 pesticides can be analyzed by LC-MS/MS with instrument detection limits (IDL) in the parts per trillion (ppt) range. Matrix-dependent IDL studies showed that due to either the low ionization efficiency or matrix effect exerted, 14 of these 191 pesticides could not be analyzed by this method. Method recovery (%R) and method detection limits (MDLs) were determined by the three laboratories using four sample matrices in replicates (N = 4). With >79% of %R data from the fortification studies in the range from 80 to 120%, MDLs were determined in the low parts per billion range with >94% of MDLs in the range from 0.5 to 5 ppb. Applying this method to the analysis of incurred samples showed that two multiple reaction monitoring (MRM) transitions may not be enough to provide 100% true positive identification of target pesticides; however, quantitative results obtained from the three laboratories had an excellent match with only a few discrepancies in the low parts per billion levels. The %R data from the fortification studies were subjected to principal component analysis and showed the majority of %R fell into the cluster of 80% < %R < 120%. Due to the matrix effect exerted by ginseng and peach, outliers were observed at the lowest spiking levels of 10 and 25 ppb. The study also showed that QuEChERS samples should be analyzed as soon as prepared or stored in a freezer to avoid any adverse affect on the analytes evaluated.
authors.affiliation: Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, Maryland 20740-3835, USA.
authors.forename: Jon
authors.initials: J
authors.lastname: Wong
authors.forename: Chunyan
authors.initials: C
authors.lastname: Hao
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Paul
authors.initials: P
authors.lastname: Yang
authors.forename: Kaushik
authors.initials: K
authors.lastname: Banerjee
authors.forename: Douglas
authors.initials: D
authors.lastname: Hayward
authors.forename: Imran
authors.initials: I
authors.lastname: Iftakhar
authors.forename: Andre
authors.initials: A
authors.lastname: Schreiber
authors.forename: Katherine
authors.initials: K
authors.lastname: Tech
authors.forename: Chris
authors.initials: C
authors.lastname: Sack
authors.forename: Michael
authors.initials: M
authors.lastname: Smoker
authors.forename: Xiangru
authors.initials: X
authors.lastname: Chen
authors.forename: Sagar C
authors.initials: SC
authors.lastname: Utture
authors.forename: Dasharath P
authors.initials: DP
authors.lastname: Oulkar
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D032084:Citrus sinensis / Q000737:chemistry; D005638:Fruit / Q000737:chemistry; D007753:Laboratories; D005894:Panax / Q000737:chemistry; D010573:Pesticide Residues / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry; D027861:Prunus / Q000737:chemistry; D011786:Quality Control; D018724:Spinacia oleracea / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014675:Vegetables / Q000737:chemistry
chemical_list: D010573:Pesticide Residues; D010936:Plant Extracts