Sustainable mining in the Arctic environment: Development of analytical methods for the determination of xanthates and application of the methods to environmental and process water samples

The high demand for raw materials has increased interest in mining in the northern latitudes. However, mining and mineral processing may pose risks to the environment, which is especially vulnerable in the Arctic region. Xanthates are a group of chemicals used in mineral processing that have recently raised concern. They can be toxic to aquatic environments, even at low concentrations. The toxicity of xanthates is mostly related to their decomposition products, such as carbon disulfide. The amounts of xanthates that are at risk of being discharged into the environment are so low that few methods are capable of reliably determining these concentrations.
The first aim of this dissertation was to develop new, selective procedures for the determination of low xanthate concentrations in process and environmental water samples. The second aim was to study the effect of cold climates on the decomposition of xanthates.
In this study, two measurement procedures were developed. Both methods were based on the determination of xanthate derivatives by high-performance liquid chromatography tandem mass spectrometry (HPLC-ICP-MS/MS), which is a relatively new technique that has not been applied to this purpose prior to this study. The results showed that the HPLC-ICP-MS/MS technique enables the determination of low xanthate concentrations. Additionally, decomposition studies showed that low temperatures significantly decrease the decomposition rate of xanthates. This study presents a pioneering step to improve the measurement procedures for the determination of xanthates. It also implies that cold climate conditions should be carefully considered when evaluating the effect of xanthates in the environment.