Preparation and Characterization of Reference Material for Determination the Total Content and Exchangeable Forms of Metallic Elements in Soils

Abstract

Reference material of soil for determination of total content of copper, iron, manganese, nickel, and zinc, according to ISO 11466-2001, and for the operationally defined method of determination of exchangeable forms of these elements according to series of standards DSTU 4770, with ammonium acetate as an extractant is prepared and characterized. The studied material demonstrated sufficient homogeneity to exchangeable forms of metals and for the total content of copper, nickel, and zinc. The homogeneity of the material to manganese and iron is insufficient due to the presence of these metals in non-uniformly distributed magnetic microparticles (<10 μm). An interlaboratory experiment, performed to obtain assigned values of the sample characteristics, demonstrated sufficiently good agreement between the laboratories. An uncertainty of the assigned value corresponds to 30–50% for exchangeable forms of copper and nickel and 10–13% for exchangeable forms of iron, manganese, and zinc. An expanded uncertainty of assigned values of the total content of copper, nickel, and zinc is sufficient for the application of the material for methods validation and internal quality control.