A voltammetric method for determining free metal activities in aqueous solutions. Part 1: direct current voltammetry of Cd, Cu, and Pb
by Arturo Aguirre-Gomez, Murray B. McBride, Wendell A. Norvell
International Journal of Environment and Pollution (IJEP), Vol. 26, No. 1/2/3, 2006

Abstract: A selective and sensitive method for determining free metal activities (M²⁺) for Cd, Cu and Pb in aqueous solutions is presented based on the Lingane and DeFord and Hume models. Electrochemical and complexation studies were carried out by direct current voltammetry (DCV) and by metal ion selective electrodes (ISE) as a reference method. A voltammetric equation was tested to evaluate (M²⁺) by varying ligand type and pH (4.5–7.5). Experimental DCV-Nernstian slopes and R² values were 29.1, 0.887 for Cd²⁺, 29.1, 0.957 for Cu²⁺ and 27.6, 0.925 for Pb²⁺, respectively. Comparison of the two independent methods gave for the DCV-ISE plots, slopes and R² values of 0.823, 0.825 for Cd, 0.996 and 0,996, for Cu and 1.10 and 0.935 for Pb respectively. The DCV- and ISE-(M²⁺) values and those predicted by MINEQL+, using reported stability constants, were statistically similar. These studies are ecologically relevant as the method allows the assessment of chemical activities of essential and toxic free heavy metals in soil solution and other synthetic and natural solutions.

Online publication date: Thu, 02-Mar-2006

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Environment and Pollution (IJEP):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com