Research progress of stable isotopic geochemistry of cadmium and zinc and its harm and control in soil and other geological bodies

This paper is the result of environmental geological survey engineering.

Objective Cadmium(Cd) and zinc(Zn) are both important mineral resources and harmful heavy metal elements. The recent development of multi–collector inductively coupled plasma mass spectrometry (MC–ICP–MS) has improved the precision of Zn isotope composition analysis in different environments. The establishment and application of non–traditional stable isotope systems such as cadmium and zinc have raised the geochemical research of cadmium and zinc to a new level, which also have become hot topics in isotope geochemistry.

Methods This paper reviews recent research progress on the analytical methods, fractionation mechanisms, isotopic compositions in different reservoirs, and application fields of Zn and Cd isotopes investigated in many studies.

Results (1) The improvement of Zn and Cd isotope analysis technology has promoted the establishment of their isotope systems. (2) The compositions of Zn isotopes in various reservoirs have been basically identified. The data for Cd isotope compositions in reservoirs and anthropogenic sources is in the period of accumulation. (3) The isotopic fractionation mechanisms of Cd and Zn mainly include mineral adsorption, biological processes, and chemical reactions, which have been applied in the indication of planetary evolution, the exploration of metallogenic mechanisms, paleoenvironmental reconstruction, and pollution source tracer. (4) The combination of multiple isotopes helps to reduce uncertainty in the analysis of heavy metal pollution sources.

Conclusions The development of new isotope analysis instruments and technologies has made the research of Zn and Cd isotopes more promising. It is expected that more work should be carried out in the near future to improve the fractionation mechanisms, compositions in partial reservoirs, and application fields.