title: Effect of sample dilution on matrix effects in pesticide analysis of several matrices by liquid chromatography-high-resolution mass spectrometry.
abstract: This study used two LC columns of different adsorbents and liquid chromatography-electrospray ionization-high-resolution mass spectrometry to study the relationship between matrix effects (ME), the LC separations, and elution patterns of pesticides and those of matrix components. Using calibration standards of 381 pesticides at three dilution levels of 1×, 1/10×, and 1/100×, 108 samples were prepared in solvent and five different sample matrices for the study. Results obtained from principal component analysis and slope ratios of calibration curves provided measurements of the ME and showed the 1/100× sample dilution could minimize suppression ME for most pesticides analyzed. Should a pesticide coeluting with matrix components have a peak intensity of 25 times or higher, the suppression for that pesticide would persist even at 1/100× dilution. The number of pesticides had enhancement ME increased with increasing dilution from 1× to 1/100×, with those early eluting, hydrophilic pesticides affected the most.
authors.affiliation: †Ontario Ministry of the Environment and Climate Change, Laboratory Services Branch, 125 Resources Road, Etobicoke, Ontario, Canada M9P 3V6.
authors.forename: Paul
authors.initials: P
authors.lastname: Yang
authors.affiliation: §ThermoFisher Scientific, 355 River Oaks Parkway, San Jose, California 95134-1908, United States.
authors.forename: James S
authors.initials: JS
authors.lastname: Chang
authors.affiliation: #U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5100 Paint Branch Parkway, College Park, Maryland 20740-3835, United States.
authors.forename: Jon W
authors.initials: JW
authors.lastname: Wong
authors.affiliation: #U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5100 Paint Branch Parkway, College Park, Maryland 20740-3835, United States.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.affiliation: #U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5100 Paint Branch Parkway, College Park, Maryland 20740-3835, United States.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Krynitsky
authors.affiliation: ⊥ThermoFisher Scientific, Hanna-Kunath-Strasse 11, 28199 Bremen, Germany.
authors.forename: Maciej
authors.initials: M
authors.lastname: Bromirski
authors.affiliation: ⊗Canadian Food Inspection Agency, Calgary Laboratory, Calgary, Alberta, Canada T2L 2L1.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D007201:Indicator Dilution Techniques; D010575:Pesticides / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation*; D053719:Tandem Mass Spectrometry
chemical_list: D010575:Pesticides
keywords: Orbitrap mass spectrometry (Orbitrap MS); high-performance liquid chromatography (HPLC); matrix effects; multiresidue pesticides analysis