Narrow Results

For the purpose of establishing an effective exploration model of antimony deposit as a final goal. minor elements in stibnite (Sb₂S₃) were analyzed by micro-PIXE. Samples were taken from the largest antimony mine in the world. Xikuangshan. Hunan. China. Measurements were carried out using 1 MeV proton to avoid the problem where low energy tail of K X-ray peaks of antimony could mask small peaks of interest. As a result. arsenic at a concentration of around 0.2 wt % was successfully detected for the stibnite crystals that contact calcite but not those that contact quartz.

Elemental concentrations of human gallstones were determined by PIXE method. Gallstone samples analyzed in this report are classified into cholesterol gallstone (pure cholesterol stone and mixed stone) and pigment gallstone (black stone and calcium bilirubinate stone). The targets were prepared by paste spreading method previously reported, which enable us to determine also volatile elements, such as halogen atoms, Hg and so on, under acidic condition. Concentrations of 17 kinds of elements were determined and characteristic distributions are presented for each type of gallstone. Ca values are the highest among of them in all types of gallstones. Pigment gallstones contain significantly higher concentrations of 9 kinds of elements (Na, Mg, S, Cl, Ca, Mn, Fe, Cu, Zn) than cholesterol gallstones. Concentrations of S, Fe, and Zn in black stones are significantly higher than those in calcium bilirubinate stones. Almost all elements contained in the samples can be determined by PIXE method, and it is supposed that the elements or some of them affect formation of gallstones and their pigment. Some samples of the pigment gallstones include I, Hg, and Pb.