Rapid Sintering Method for Preparing Matrix-Matched Reference Materials in LA-MC-ICP-MS - An Example of Hafnium.

Matrix effects can significantly bias Hf isotopic ratios in situ Hf isotope analyses using laser ablation (LA-) multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS), necessitating the use of matrix-matched reference materials for accurate microanalysis. This work introduces a novel fast hot-pressing (FHP) sintering method to produce such reference materials efficiently for in situ analysis. By optimizing sintering temperatures, FHP technology enables the rapid preparation of in situ analysis reference materials with dense structures and homogeneous Hf isotopic compositions. The Hf isotope compositions of the FHP-sintered cassiterite and rutile were assessed using femtosecond LA-MC-ICP-MS, with results consistent with those determined by MC-ICP-MS. The homogeneity tests reveal minimal heterogeneity among the sintered sample tablets, suggesting their potential as reference materials for in situ Hf isotopic determination in cassiterite and rutile. The FHP method offers a rapid, cost-effective alternative to traditional preparation methods, producing large quantities of reference materials with compact structures. This procedure provides great promise for the synthesis of various isotope matrix-matched reference materials.