A Review of Advances in the Study of Non-Traditional Antimony Isotopes in the Earth Sciences

Non-traditional antimony (Sb) isotopes play a pivotal role in environmental pollution monitoring, paleoenvironmental reconstruction, resource exploration, and other fields, offering a unique perspective for tracing Sb sources, migration pathways, and geochemical processes. In this paper, the geochemical behaviors, analytical testing techniques, and fractionation mechanisms of Sb and its isotopes are systematically summarized, as well as their applications in geoscience. Previous studies have improved the analytical precision of Sb isotope measurements to 0.01‰ via multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). Based on this, redox reactions, adsorption, biological processes, and evaporation have been identified as the core mechanisms driving Sb isotope fractionation: ¹²¹Sb is enriched in low-valence states, adsorbed phases, or reaction products, while ¹²³Sb remains in high-valence states, aqueous phases, or reactants. In addition, reaction rate, temperature, and other factors are key to regulating such fractionation. In environmental applications, Sb isotopes enable accurate source tracing in pollution monitoring—for example, identifying multiple Sb sources in soils (e.g., rock weathering and atmospheric deposition) and elucidating their migration pathways, which are governed by adsorption onto organic matter and Fe-Mn oxides. In paleoenvironmental studies of sedimentary rocks, antimony isotopes trace the redox conditions of ancient oceans and the enrichment of ore-forming elements; in ore-forming studies of oil reservoirs, they reveal interaction mechanisms between hydrothermal fluids and organic matter; in mineral deposit exploration, they track hydrothermal migration pathways and the evolution of multistage mineralization; and in coal seam studies, they elucidate the sources of ore-forming fluids and hydrothermal effects on Sb enrichment. With advances in analytical techniques and improved measurement precision, Sb isotopes show tremendous application potential in geological research and serve as an interdisciplinary tool linking geoscience and environmental science. Future research should integrate multiple isotope systems to develop more comprehensive tracing models, thus providing precise technical support for resource exploration and pollution control. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202504160092.