Preparation of a new GSJ geochemical reference material: JSO-2 soil

In order to provide a soil reference material which contains known chemical forms of miner and trace elements, thirty-one reagent materials, mostly in oxides, were artificially added to a natural soil collected from the Kanto loam formation near Geological Survey of Japan (GSJ). The concentrations of added minor and trace elements were about 1000 mu g/g for As, Co, Cr, Cu, Mo, Ni, Pb, V, W, Y, Zn, and Zr, 100 mu g/g for B, Be, Bi, Br, Cd, Sb, Sn, and Ta, 10 mu g/g for Ag, Hg, I, In, Se, Te, and T1, and 1 mu g/g for Au, Pd, Pt, and Rh, respectively. The ingredients were diluted with a small amount of feldspar powder and ground in an agate mortar, then diluted with the same feldspar powder sequentially and ground and mixed in an agate mortar or a small ball mill thoroughly at each dilution step. Finally, a mixture of about 12 kg was diluted with 108 kg of well-dried natural soil using a large ball mill. The sample was screened with a 246 mu m (60 mesh) opening of a stainless-steel sieve, and mixed well before packing in glass bottles. A homogeneity test showed that all of the elements studied were homogeneously distributed. Forty-three major, minor and trace elements were determined, and the results were tabulated together with the analytical methods and the outline of sample treatment procedures. Analytical results of the mineral composition by X-ray diffraction are also presented.