1. Cadmium Isotope Fractionation During Adsorption onto Manganese Oxides Gabriela Montañez Mentors: Laura Wasylenki and Ariel Anbar

2. Nutrient to some marine organisms Toxic metal in environment

3. Why adsorption? Adsorption to particles governs cadmium concentration in natural waters Cadmium is immobilized if strongly adsorbed Will cadmium isotopes fractionate during adsorption? Manganese oxide Cd 2+

4. What are isotopes? Isotopes are atoms of an element that have the same number of protons but different numbers of neutrons Cadmium has isotopes of mass 106, 108, 110, 111, 112, 114, 116 Will light or heavy isotopes preferentially adsorb to manganese oxides?

5. Seawater vs. natural ferromanganese crusts Horner et al. (2008) sampled ferromanganese sediments and seawater at depth No fractionation was found What would a simple controlled laboratory experiment show?

6. Procedure Cadmium stock MnOx stock pH ~ 6 Measure isotope ratio on solution and solid after separation

7. Mass Spectrometer 108 114

8. Fractionation!  114/108Cd (‰)

9. Implications and Future Work Fractionation tells us that the isotopes might give us a new tool to track cadmium as it moves between water and sediments in the environment Next steps: –try adsorption to other minerals –find contaminated aquifer to investigate cadmium isotope variations in the real world