An Investigation of the Marine Geochemistry of Gold
Abstract
An analytical method has been developed for the analysis of gold (Au) in seawater and was applied to a suite of samples in order to conduct a preliminary assessment of the marine geochemical behavior of Au. The method involved preconcentration by anion exchange of Au complexed with cyanide ion and detection by flow injection-inductively coupled plasma quadrupole mass spectrometry (FI-ICPMS). An aliquot of a radiotracer was added to each sample to monitor recoveries. Analysis by FI-ICPMS resulted in a practical detection limit, expressed as the concentration of Au in seawater, of about 10 fmol/liter for a four liter preconcentrate. Corrections for the stable Au in the radiotracer and that contributed by reagents were significant, constituting up to 60% of the overall signals measured. Reproducibility, based in the analyses of five four-liter samples of Mediterranean seawater obtained from a single 30- liter Niskin bottle, was about 15% at the 140 fmol/liter level. Gold profiles from the Atlantic Gulf Stream, Northeast Pacific, Mediterranean and Black Seas and hydrothermal fluids from 21 N, on the East Pacific Rise were analyzed. In general, the concentrations of Au in seawater are nearly three orders of magnitude less than reported in the literature prior to 1988. Gold is a non- conservative element in seawater. It does not appear to undergo appreciable recycling in the water column under oxic conditions as is evidenced by its fairly homogeneous distribution over the water column and similar average values in the Atlantic.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1989
- Accession Number
- ADA216522
Entities
People
- Kelly K. Falkner
Organizations
- Woods Hole Oceanographic Institution