Electrochemical screening procedure for arsenic contaminated soils

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Electrochemistry

Background:

• Industrial development leads to soil contamination with heavy metals and arsenic.
• Traditional methods for soil analysis are time-consuming and can alter sample chemistry.

Purpose of the Study:

• To develop a rapid and accurate method for detecting arsenic and heavy metals in contaminated soils.
• To avoid sample manipulation that could change the original chemical forms of contaminants.

Main Methods:

• Voltammetry of immobilized microparticles was employed.
• A small soil sample was directly attached to a carbon paste working electrode.
• Anodic differential pulse voltammetry was performed without prior sample dissolution or extraction.

Main Results:

• The method successfully identified lead (Pb), copper (Cu), and both arsenic(V) (As(V)) and arsenic(III) (As(III)) species.
• Arsenic(III) was detectable at concentrations above 0.001% (as As(2)O(3)).
• The presence of iron(III) significantly enhanced the signal by 10 times, improving detectability.

Conclusions:

• Voltammetry of immobilized microparticles offers a direct and efficient approach for analyzing heavy metals and arsenic in contaminated soils.
• This method preserves the original chemical state of contaminants, providing more reliable results.
• The technique's sensitivity is influenced by matrix components like iron(III).