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 o f 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 amo unt 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 o f about 12 kg was diluted with 108 kg of well-dried natural soil using a la rge 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 homogeneousl y distributed. Forty-three major, minor and trace elements were determined, and the results were tabulated together with the analytical methods and th e outline of sample treatment procedures. Analytical results of the mineral composition by X-ray diffraction are also presented.