title: Development of soybean certified reference material for pesticide residue analysis.
abstract: A soybean certified reference material for pesticide residue analysis was developed by the National Metrology Institute of Japan. Three organophosphorus (diazinon, fenitrothion, chlorphyrifos) and one pyrethroid (permethrin) pesticides were sprayed on soybeans three times before harvest. These soybeans were freeze pulverized, homogenized, bottled, and sterilized by γ-irradiation to prepare the candidate material. Three isotope-dilution mass spectrometric methods that varied in terms of the solvents used for extraction of the target pesticides, the clean-up procedure, and the injection techniques and columns used for quantification via gas chromatography/mass spectrometry were applied to the characterization. Each target pesticide was quantified by two of these analytical methods, and the results were in good agreement. Homogeneity and stability assessment of the material demonstrated that the relative standard uncertainties due to the inhomogeneity and the instability for an expiry date of 55 months were 1.89-4.00% and 6.65-11.5%, respectively. The certified pesticide concentrations with expanded uncertainties (coverage factor k=2, approximate 95% confidence interval) calculated using the results of the characterization and the homogeneity and stability assessment were 21.7 ± 3.2 μg/kg for diazinon, 88 ± 21 μg/kg for fenitrothion, 11.1 ± 3.2 μg/kg for chlorpyrifos, and 20.1 ± 4.3 μg/kg for permethrin (as the sum of the constituent isomers).
authors.affiliation: National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 3, Umezono, Tsukuba, Ibaraki 305-8563, Japan. Electronic address: t-yarita@aist.go.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yarita
authors.affiliation: National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 3, Umezono, Tsukuba, Ibaraki 305-8563, Japan.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Otake
authors.affiliation: National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 3, Umezono, Tsukuba, Ibaraki 305-8563, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Aoyagi
authors.affiliation: National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 3, Umezono, Tsukuba, Ibaraki 305-8563, Japan.
authors.forename: Youko
authors.initials: Y
authors.lastname: Kuroda
authors.affiliation: National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 3, Umezono, Tsukuba, Ibaraki 305-8563, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Numata
authors.affiliation: Japan Food Research Laboratories, 6-11-10, Nagayama, Tama, Tokyo 206-0025, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Iwata
authors.affiliation: Japan Food Research Laboratories, 6-11-10, Nagayama, Tama, Tokyo 206-0025, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Watai
authors.affiliation: The General Environmental Technos Co., Ltd. (KANSO Technos), 3-1-1, Higashikuraji, Katano, Osaka 576-0061, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mitsuda
authors.affiliation: The General Environmental Technos Co., Ltd. (KANSO Technos), 3-1-1, Higashikuraji, Katano, Osaka 576-0061, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujikawa
authors.affiliation: The General Environmental Technos Co., Ltd. (KANSO Technos), 3-1-1, Higashikuraji, Katano, Osaka 576-0061, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Ota
mesh_terms: D013058:Mass Spectrometry / Q000379:methods; D010573:Pesticide Residues / Q000032:analysis*; D012015:Reference Standards; D013025:Glycine max / Q000737:chemistry*; D035501:Uncertainty
chemical_list: D010573:Pesticide Residues
keywords: Certification; Certified reference material (CRM); Homogeneity assessment; Isotope-dilution mass spectrometry; Organophosphorus pesticide; Pyrethroid pesticide; Stability assessment; Uncertainty estimation