Determination of Hf-Sr-Nd isotopic ratios by MC-ICP-MS using rapid acid digestion after flux-free fusion in geological materials

In this study, we established a rapid acid digestion for determining Hf-Sr-Nd isotopic ratios of geological samples by using MC-ICP-MS. Conditions of 1600 A degrees C for 1 min and 1400 A degrees C for 1 min were adopted for fusing intrusive rocks and extrusive rocks, respectively. The rapid acid digestion technique is superior in digestion time compared with high-pressure PTFE bomb method. The procedural blanks of the method were also lower than that flux fusion. Replicate analyses of international certified reference materials (CRMs) indicate that isotopic ratios of Hf-176/Hf-177, Sr-87/Sr-86 and Nd-143/Nd-144 agree well with previously published data. The external reproducibility (2SD, n = 5) of ten CRMs are +/- 0.000030 for Sr-87/Sr-86, +/- 0.000030 for Nd-143/Nd-144, and +/- 0.000018 for Hf-176/Hf-177.