USE OF PARTICLE-INDUCED X-RAY-EMISSION FOR EVALUATION OF COMPETITIVE METAL-BINDING ON ALGAE

Elemental concentrations of a unicellular alga, Chlorella vulgaris, we re evaluated by particle-induced X-ray emission (PIXE). The probed alg al cells generated a significant amount of phosphorus and sulfur X-ray emission. Phosphorus- and sulfur-containing compounds can provide pot ential binding sites for metal ions. Competitive binding of six metal ions, Ag, Ba, Cd, Cu, Hg, and Ph, to the algae was studied. It was fou nd that Ag, Ba, Cd, Cu, and Pb are attached to a similar binding site with a binding efficiency varying in the sequence Pb > Cu > Ag > Cd > Ba. The binding of tig to algae involves a different binding site. Sil ver was found to increase the binding of mercuric chloride to the alga e. (C) 1997 Academic Press.