“…The distribution and concentration of elements in single bacterial cells was determined using synchrotron-based XRF (Kemner et al, 2004). XRF was used to determine the concentrations of 16 elements (from K to Pb) in powdered aquatic plants (Sokolovskaya et al, 2000;Kipriyanova et al, 2001) as well as to map the distribution of Se in the leaves and stems of Astragalus bisulcatus (Pickering et al, 2000). Other work has investigated the distribution of Mn, Fe, Ni, Cu, Zn and Rb in the roots of Salix nigra (black willow) irrigated with spill water from a radioactive settling pond (Punshon et al, 2003), Cr in the roots of Trifolium brachycalicinum (Howe et al, 2003), P to Zn in Plantago lanceolata roots and the associated arbuscular mycorrhizal fungus Glomus mosseae (Yun et al, 1998), and K, Mn, Fe, Cu and Zn in tobacco flowers and leaves from plants both lacking and overexpressing nicotianamine aminotransferase (Takahashi et al, 2003).…”