title: Measurement of pyrethroids and their environmental degradation products in fresh fruits and vegetables using a modification of the quick easy cheap effective rugged safe (QuEChERS) method.
abstract: Pyrethroid insecticides are used extensively in agriculture, and they, as well as their environmental degradates, may remain as residues on foods such as fruits and vegetables. Since pyrethroid degradates can be identical to the urinary markers used in human biomonitoring, it is important to understand the contribution of these degradates when studying sources of human pyrethroid exposure. We modified the widely used Quick Easy Cheap Effective Rugged Safe (QuEChERS) method to measure several current-use pyrethroids (cis/trans-permethrin, cypermethrin, deltamethrin, esfenvalerate, bifenthrin, cyfluthrin, and cyhalothrin) and their environmental degradation products (3-PBA, cis/trans-DCCA, 4-F-3-PBA, DBCA, and MPA) in selected fresh fruits and vegetables. Using fortified samples, we determined extraction efficiencies from: tomatoes, oranges (whole, peeled, and rind), grapes, apples, bananas (peeled and rind only), onions, lettuce, green peppers, carrots and broccoli. For a subset of these food items (apples, grapes, tomatoes, lettuce and banana peel), we also established limits of detection (MDLs) and quantitation (MQLs). Each sample was homogenized (1kg) then spiked with the target pyrethroids and their degradation products. Sub-samples (15g) were extracted with acetonitrile, then salted out and partitioned with NaCl and MgSO4. The extract was divided and further cleaned using solid phase extraction (SPE) cartridges containing either graphitized non-porous carbon (pyrethroids) or C18 (degradation products). Sample analysis was via liquid chromatography/tandem mass spectrometry (LC-MS/MS). Considering the mean recoveries each of the 14 analytes in all 13 matrices: 42% of the recoveries were ≥90%, 70% were ≥80%, and 90% were ≥70%. All MDL's were less than 100ng/kg, except 3-PBA (132ng/kg, tomato), MPA (129ng/kg, tomato), and trans-permethrin (141ng/kg, banana peel). We then applied the method to non-spiked samples (subset of 5 for which the MDLs/MQLs had been determined) collected weekly for four weeks from local supermarkets. At least one pyrethroid was present in measureable concentrations in all matrices except banana peels. In contrast, the only degradation products detected were cis/trans-DCCA, in one lettuce sample.
authors.affiliation: Oak Ridge Institute for Science and Education Fellow at the U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Research Triangle Park, NC 27711 USA.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Li
authors.affiliation: U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, USEPA MD D205-05, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711 USA.
authors.forename: Marsha K
authors.initials: MK
authors.lastname: Morgan
authors.affiliation: U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards Health and Environmental Impacts Division, Research Triangle Park, NC 27711 USA.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Graham
authors.affiliation: U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, USEPA MD D205-05, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711 USA. Electronic address: starr.james@epa.gov.
authors.forename: James M
authors.initials: JM
authors.lastname: Starr
mesh_terms: D000328:Adult; D001565:Benzoates / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D002853:Chromatography, Liquid / Q000379:methods; D003362:Cost-Benefit Analysis; D004781:Environmental Exposure / Q000032:analysis / Q000517:prevention & control; D004784:Environmental Monitoring / Q000191:economics / Q000379:methods; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D007306:Insecticides / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D008875:Middle Aged; D015394:Molecular Structure; D010573:Pesticide Residues / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D011722:Pyrethrins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods; D014675:Vegetables / Q000737:chemistry*; D055815:Young Adult
chemical_list: D001565:Benzoates; D007306:Insecticides; D010573:Pesticide Residues; D011722:Pyrethrins; C017618:3-phenoxybenzoic acid
keywords: Environmental degradates; LC-MS/MS; MDLs/MQLs; Pyrethroids; QuEChERS method; Solid phase extraction