The marine geochemistry of trace metals
type: CreativeWork
description: The marine geochemical cycles of iron, copper, nickel, and cadmium were studied in order to provide a basis for oceanographic models for trace metals. Copper, nickel, and cadmium can be determined in a 100 ml seawater sample using cobalt pyrrolidine dithioacarbamate chelate coprecipitation and graphite atomizer atomic absorption spectrometry. Concentration ranges likely to be encountered and estimated (1δ) analytical precisions are copper, 1 to 6 nanomole/kg (±0.1); nickel, 3 to 12 nanomole/kg (±0.3); and cadmium, 0. 0 to 1.1 nanomole/kg (±0.1). The technique may be applied to freshwater samples with slight modification. A survey of several east coast U. S. estuaries established that an iron removal process occurs commonly when rivers mix with seawater. Laboratory mixing experiments using water from the Merrimack River (Mass.) and the Mullica River (New Jersey) demonstrated that rapid iron precipitation occurs as negatively-charged iron-organic colloids react with seawater cations and coagulate. This phenomenom was modeled using a synthetic, organic-stabilized colloidal suspension of goethite. The generality of the mechanism suggests that the world-average net river input of iron to the oceans is less than 1 μmole/kg of river water, an order of magnitude below previous estimates. Profiles of cadmium were obtained for 3 GEOSECS stations in the Pacific Ocean. Cadmium shows a consistent linear correlation with phosphate which demonstrates that cadmium is regenerated in a shallow cycle within the water column. The water column correlation is consistent with data on cadmium in marine organisms. Cadmium is enriched in upwelling regions which explains reports of cadmium enrichment in plankton from the Baja California upwelling region. Copper and nickel measurements have been made for three profiles from the Pacific Ocean. Observed copper concentrations range from 1 to 6 nanomole/kg; nickel varies from 3 to 12 nanomole/kg. Copper and nickel are removed from surface waters b…
abstract: The marine geochemical cycles of iron, copper, nickel, and cadmium were studied in order to provide a basis for oceanographic models for trace metals. Copper, nickel, and cadmium can be determined in a 100 ml seawater sample using cobalt pyrrolidine dithioacarbamate chelate coprecipitation and graphite atomizer atomic absorption spectrometry. Concentration ranges likely to be encountered and estimated (1δ) analytical precisions are copper, 1 to 6 nanomole/kg (±0.1); nickel, 3 to 12 nanomole/kg (±0.3); and cadmium, 0. 0 to 1.1 nanomole/kg (±0.1). The technique may be applied to freshwater samples with slight modification. A survey of several east coast U. S. estuaries established that an iron removal process occurs commonly when rivers mix with seawater. Laboratory mixing experiments using water from the Merrimack River (Mass.) and the Mullica River (New Jersey) demonstrated that rapid iron precipitation occurs as negatively-charged iron-organic colloids react with seawater cations and coagulate. This phenomenom was modeled using a synthetic, organic-stabilized colloidal suspension of goethite. The generality of the mechanism suggests that the world-average net river input of iron to the oceans is less than 1 μmole/kg of river water, an order of magnitude below previous estimates. Profiles of cadmium were obtained for 3 GEOSECS stations in the Pacific Ocean. Cadmium shows a consistent linear correlation with phosphate which demonstrates that cadmium is regenerated in a shallow cycle within the water column. The water column correlation is consistent with data on cadmium in marine organisms. Cadmium is enriched in upwelling regions which explains reports of cadmium enrichment in plankton from the Baja California upwelling region. Copper and nickel measurements have been made for three profiles from the Pacific Ocean. Observed copper concentrations range from 1 to 6 nanomole/kg; nickel varies from 3 to 12 nanomole/kg. Copper and nickel are removed from surface waters b…
author: Boyle, Edward A.
language: en_US
keywords: Geochemistry, Chemical oceanography, Trace elements in water, Chain (Ship : 1958-) Cruise CH115
date published: 1976-04
date modified: 2026-07-27T22:05:21Z
provider: Woods Hole Oceanographic Institute
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massachusetts Institute of Technology and Woods Hole Oceanographic Institution

PropertyValue
property ID: Handle
value: https://hdl.handle.net/1912/1294

PropertyValue
property ID: DOI
value: 10.1575/1912/1294