Research interests include a broad range of topics in Marine and Environmental Chemistry, including the role of natural nanoparticles in the biogeochemical cycling of trace substances, tracer applications using radioactive and stable isotopes, relationships between trace element and natural organic matter biogeochemistry, and the importance of exopolymeric substances and hydroxamate siderophores for trace element binding and removal from natural waters. That involves learning from new techniques, approaches and concepts that are used in related fields and applying them to solve questions in biogeochemistry and environmental science. Current themes of research are: Trace element speciation and cycling. Tracer applications in natural water systems using stable and radioactive isotopes. Sediment-water and particle-water interactions, with emphasis on colloids. Natural organic matter geochemistry. Metal-organic matter binding. Mobility of radioactive and toxic trace contaminants in surface waters, sediments and ground water. Applications of atomic force microscopy, accelerator, thermal ionization, and gas chromatography mass spectrometry in marine and environmental chemistry and geochemistry.