Development of a Matrix-Matched Sphalerite Reference Material (MUL-ZnS-1) for Calibration of In Situ Trace Element Measurements by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry

Sphalerite (ZnS) is an abundant ore mineral and an important carrier of elements such as Ge, Ga and In used in high-technology applications. In situ measurements of trace elements in natural sphalerite samples using LA-ICP-MS are hampered by a lack of homogenous matrix-matched sulfide reference materials available for calibration. The preparation of the MUL-ZnS1 calibration material containing the trace elements V, Cr, Mn, Co, Ni, Cu, Ga, Ge, As, Se, Mo, Ag, Cd, In, Sn, Sb, Tl and Pb besides Zn, Fe and S is reported. Commercially available ZnS, FeS, CdS products were used as the major components, whereas the trace elements were added by doping with single-element ICP-MS standard solutions and natural mineral powders. The resulting powder mixture was pressed to pellets and sintered at 400 degrees C for 100h using argon as an inert gas. To confirm the homogeneity of major and trace element distributions within the MUL-ZnS1 calibration material, measurements were performed using EPMA, solution ICP-MS, ICP-OES and LA-ICP-MS. The results show that MUL-ZnS-1 is an appropriate material for calibrating trace element determination in sphalerite using LA-ICP-MS.