Isotopic tracing of sources and cycling of hazardous metal mixtures.
Project 2 of the Columbia Northern Plains Superfund Research Program will develop the spatial and temporal distribution of uranium and selenium isotope ratios or “isoscapes,” from private groundwater wells, which will reveal the sources and mechanisms of hazardous metal cycling in the aquifers, and the evolution of existing uranium and selenium plumes. This study will also develop the use of isotope ratios as novel biomarkers of uranium and selenium exposure in humans linked to an environmental source.
Nickel Isotopes in High Temperature Rocks
This project focuses on using the fractionation of stable Ni isotopes in high temperature rocks to investigate compositions of mantle sources and mantle mixing. We use double spike to correct for instrumental mass bias.
Rock samples are dissolved in acid and then purified over several days using a series of ion exchange columns until only Ni remains. The pure Ni sample is analysed with a MC-ICPMS, and the amounts of the different isotopes are measured and compared to the same isotopes in a standard.
Zinc isotope constraints on zinc vvailability in soil-crop system
Zinc (Zn) deficiency due to insufficient Zn intake affects 1/3 of world’s population. By 2050 additional 138 million people is estimated to suffer from Zn deficiency due to the reduction of global availability of Zn. Therefore, there is an urgent need to find sustainable ways to combat Zn deficiency in humans which is strongly correlated to dietary Zn intake from crops grown on Zn deficient soils.