title: Characterization of NIES CRM No. 23 Tea Leaves II for the determination of multielements.
abstract: A candidate environmental certified reference material (CRM) for the determination of multielements in tea leaves and materials of similar matrix, NIES CRM No. 23 Tea Leaves II, has been developed and characterized by the National Institute for Environmental Studies (NIES), Japan. The origin of the material was tea leaves, which were ground, sieved through a 106-microm mesh, homogenized, and then subdivided into amber glass bottles. The results of homogeneity and stability tests indicated that the material was sufficiently homogeneous and stable for use as a reference material. The property values of the material were statistically determined based on chemical analyses by a network of laboratories using a wide range of methods. Sixteen laboratories participated in the characterization, and nine certified values and five reference values were obtained. These property values of the candidate CRM, which are expressed as mass fractions, were close to the median and/or mean values of the mass fractions of elements in various tea products. The candidate CRM is appropriate for use in analytical quality control and in the evaluation of methods used in the analysis of tea and materials of similar matrix.
authors: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan. mori.ikuko@nies.go.jp
authors: Ikuko
authors: I
authors: Mori
authors: Miyuki
authors: M
authors: Ukachi
authors: Kimiyo
authors: K
authors: Nagano
authors: Hiroyasu
authors: H
authors: Ito
authors: Jun
authors: J
authors: Yoshinaga
authors: Masataka
authors: M
authors: Nishikawa
mesh_terms: D018515:Plant Leaves / Q000737:chemistry*; D011786:Quality Control; D012015:Reference Standards; D013662:Tea / Q000737:chemistry* / Q000592:standards*; D014131:Trace Elements / Q000032:analysis* / Q000592:standards*
chemical_list: D013662:Tea; D014131:Trace Elements