Editorial: “Metal Isotope Analytical Chemistry for Geological and Environmental Sample”

Abstract

Metal isotopes are important tracers for various geological and environmental processes. Accurate determination of metal isotope ratios is a hot topic at present, evidently from the rapid growth in the number of related publications in geoscience and environmental sciences. High precision isotopic analysis techniques based on modern inorganic mass spectrometry (TIMS, MC-ICP-MS, SIMS, and LA-ICP-MS/MC-ICP-MS) have been developed, greatly driving the developments in geoscience and environmental science over the past half century. Among these activities, in situ isotopic analysis and dating analytical techniques for special minerals (e.g., zircon, garnet, clinopyroxene, pyrite, chalcopyrite and ferromanganese nodule) based on LA-MC-ICP-MS, LA-ICP-MS and SIMS are rising fast in geoscience due to their high spatial resolution, fast analysis, small sample size, minimal sample preparation and low contamination. To obtain high precision, many key technical issues must be thoroughly investigated such as matrix effects, sources of interfering substances, isotopic fractionation correction, matrix-match standards and sensitivity improvements. In addition, sample purification techniques with low blank, low cost, high recovery, high selectivity, and high sample throughput are crucial for high precision metal isotope ratio measurements for bulk analysis in geological samples. The Cu isotope ratio in Cu-dominated minerals is a powerful tool to trace the ore-forming source and study metallogenic system evolution. In previous studies, rigorous sample purification is indispensable, but it is time-consuming and tedious. One paper in this special issue has reported a novel analytical method for the direct determination of Cu isotope ratios without column chemistry. The influence of matrix elements on the final Cu isotope ratios can be corrected by using a C-SSBIN with Ga as an internal standard. The proposed method has a significant advantage for the economical and efficient determination of Cu isotopic ratios in Cu-dominated minerals. Due to large relative mass difference between Li and Li, Li isotope ratio is of great interest in many fields including geochemistry, astrophysics and the nuclear industry. A new sample preparation technique for Li isotope ratio measurements based on a single-column AGMP50 cation resin is reported in one of collections in this special issue. The proposed method is rapid and ideally suited for Li separation from complex geological sample matrix prior toMC-ICP-MS analysis. The proposed method shows great potential in study conventional silicate materials and trace both high-temperature magma processes and low-temperature weathering processes. Reference materials (RMs) play an important role in isotopic analysis for the validation of analytical methods employed to ensure the quality of data. The commonly used Cu isotopic standard Edited and reviewed by: Alberto Salomone, University of Turin, Italy