title: Organophosphate levels in apple composites and individual apples from a treated Canadian orchard.
abstract: Azinphos-methyl, phosalone, and phosmet were applied individually to separate rows of trees within a commercial apple orchard in Quebec, Canada, during the 2003 agricultural season. Apples were collected for residue analysis immediately prior to the harvesting of the remaining apples for market distribution and were prepared for analysis as both individual apples and as composites of eight individuals. Analysis of the three applied compounds, as well as five organophosphate insecticides that were not applied, was performed using gas chromatography-mass spectrometry. Azinphos-methyl, phosalone, and phosmet, which were applied, were detected in all samples analyzed at concentrations ranging from 0.004 ng/g to 2260 ng/g. Methidathion was not observed in any sample. Chlorpyrifos, diazinon, dimethoate, and malathion concentrations ranged from below method detection limits to 0.71 ng/g, and the detection frequency for these compounds ranged from 20% to 100%. Residues measured in this study were all below the Canadian maximum residue limit for apples. Variability factors ranged from 2 to 19 for all compounds observed in this study. Composite samples may not accurately reflect the extremes of exposure from consumption of single servings of apples.
authors.affiliation: Food Research Division, Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, 2203D Tunney's Pasture, Ottawa, ON, Canada K1A 0L2. thea_rawn@hc-sc.gc.ca
authors.forename: Dorothea F K
authors.initials: DF
authors.lastname: Rawn
authors.forename: Sue C
authors.initials: SC
authors.lastname: Quade
authors.forename: J Brian
authors.initials: JB
authors.lastname: Shields
authors.forename: Giacomo
authors.initials: G
authors.lastname: Conca
authors.forename: Wing-Fung
authors.initials: WF
authors.lastname: Sun
authors.forename: Gladys M A
authors.initials: GM
authors.lastname: Lacroix
authors.forename: Mark
authors.initials: M
authors.lastname: Smith
authors.forename: André
authors.initials: A
authors.lastname: Fouquet
authors.forename: André
authors.initials: A
authors.lastname: Bélanger
mesh_terms: D002170:Canada; D005506:Food Contamination / Q000032:analysis; D005638:Fruit / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D007306:Insecticides / Q000008:administration & dosage* / Q000032:analysis*; D027845:Malus / Q000737:chemistry*; D010755:Organophosphates / Q000008:administration & dosage* / Q000032:analysis*
chemical_list: D007306:Insecticides; D010755:Organophosphates