This study is the second year of the project “Tracing sources of Cu in contaminated soils of Taiwan with stable Cu isotopic ratios.” We aim to develop a high-precision Cu isotope technique for a variety of environmental samples, including soils, river sediments, and water samples, and further study possible sources of metal pollutions. In this project, we have (1) reviewed/summarized the literature regarding the analytical techniques and applications of stable Cu isotope for tracing sources of Cu in contaminated soils, (2) developed a high-precision stable Cu isotopic technique on a variety of environmental samples and drafted the protocol for Cu isotope analysis in soils, and (3) trained several EAL staffs for the analytical techniques developed in this project. On the other hand, we also applied the developed analytical protocols to the soil samples collected from two sites in Changhua County, where the farmland soils were polluted by local industrial sources. We have investigated samples at both sites after farmland remediation, including soils, sediments, and possible metal dust sources. The preliminary results show that different sources of Cu can be identified with the implementation of Cu isotope ratios, suggesting that the stable Cu isotope ratio can be a powerful tool for metal source tracing in Cu-contaminated soils. However, efforts are still necessary, such as the establishment of the Cu isotope database, the coupling of radiogenic isotopes (e.g. Pb) or multiple isotope approaches, to fully understand Cu sources and transport pathways in the environment.

MC-ICP-MS, Soil, Metal pollution, Cu isotopes