A SIMPLE METHOD FOR PRECISE DETERMINATION OF 23 TRACE ELEMENTS IN GRANITIC ROCKS BY ICP-MS AFTER LITHIUM TETRABORATE FUSION

Abstract

An improved alkali fusion method followed by HF-HNO3-HClO4 treatment is performed for simultaneous determination of 23 trace elements (Sr, Y, Zr, Nb, Ba, Hf, Ta, Th, U, and REE) by ICP-MS in rock reference materials: basaltic rocks (JB-2, JB-3) and granitic rocks (JG-1a, JG-2, JG-3). Our improved method offers several advantages including: (1) suppression of whitish precipitates probably composed of insoluble fluorides by addition of HClO4, (2) simple and reliable preparation procedure, (3) instrument calibration which enables straightforward simultaneous multi-elemental analysis, and (4) the very low background levels by using pure lithium tetraborate flux. We obtained the analytical results with a reproducibility of mostly <2 % (1σ for the basaltic rocks and <7 granitic rocks. higher relative standard deviation (rsd) values may be attributed to sample heterogeneity of coarse-grained analytical results demonstrate that zr hf abundances are consistent with compiled ree concentrations agree well recently published data, suggesting li2B4O7 fusion method applied in the present study is suitable for the analysis of the granitic rocks.