Iron(II) in rainwater, snow, and surface seawater from a coastal environment

Using a newly developed HPLC method for the determination of Fe(II) concentration in a variety of aqueous environmental samples we found that Fe(II) accounts for 50–74% of the total filterable Fe in coastal surface seawater, 25–53% in rain samples, and 25–74% in snow collected from the vicinity of Massachusetts Bay, and Boston Harbor. We also found the residence time of Fe(II) in natural seawater to follow pseudo-first-order kinetics with an apparent half-life on the order of 30–70 min, much longer than previously thought. The observation of high Fe(II) concentrations and long apparent half-life reflect the product of as yet undefined chemical processes occurring in either atmosphere and/or seawater environments. These significant concentrations of Fe(II) may represent an important source of Fe influencing phytoplankton growth in coastal seawater.