GC53I-02
Copper, iron and the organic ligands that bind them - updates from San Francisco Bay and beyond
Friday, 18 December 2015: 13:55
3003 (Moscone West)
Kristen N Buck1, Randelle Bundy2,3, Dondra Biller4, Kenneth W Bruland4 and Katherine Barbeau2,5, (1)University of South Florida, College of Marine Science, St. Petersburg, FL, United States, (2)Scripps Institution of Oceanography, Geosciences Research Division, La Jolla, CA, United States, (3)Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA, United States, (4)University of California Santa Cruz, Santa Cruz, CA, United States, (5)University of California San Diego, La Jolla, CA, United States
Abstract:
Building on more than 30 years of measurements in San Francisco Bay by Russ Flegal and others, the concentrations of dissolved manganese, iron, cobalt, nickel, copper, zinc, cadmium and lead were determined from a suite of water quality monitoring program stations in North, Central and South Bay using inductively coupled plasma- mass spectrometry following preconcentration on a Nobias-chelate PA1 resin. Given the importance of organic ligands in governing iron solubility and copper bioavailability in natural waters, the organic complexation of dissolved iron and copper in these samples was determined from multiple analytical windows applied to competitive ligand exchange- adsorptive cathodic stripping voltammetry. This study constitutes the first dataset of iron speciation in San Francisco Bay and expands upon prior work evaluating the potential for copper toxicity in this urbanized estuary. Recent advances in voltammetric techniques emerging from a Scientific Committee on Oceanic Research (SCOR) working group on metal-binding ligands in the marine environment, and insights gained from high-resolution ligand measurements from the U.S. GEOTRACES program, highlight how metal-binding ligands in San Francisco Bay compare with those of the coastal and open ocean.
