Anodic stripping voltammetry enhancement by redox magnetohydrodynamics

by Clark, Emily A.; Fritsch, Ingrid

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The effect of an external magnetic field on linear scan anodic stripping voltammetry (ASV) in solutions of 10(-6)-10(-7) M concentrations of lead, cadmium, and copper at mercury films on glassy carbon electrodes has been investigated. A high concentration of Hg2+ was added to the analyte solution to induce a large cathodic current during the deposition step. Therefore, a large Lorentz force from the net flux of charge through the magnetic field resulted in convection due to magnetohydrodynamics. The faster delivery of analytes to the mercury film electrode during deposition caused an increase in the anodic stripping peaks. The effect of varying Hg2+ concentrations (0-60 mM) and magnetic field strengths (0-1.77 T) on the enhancement of the stripping peaks was investigated. Enhancements as large as 129% for peak currents and 167% for peak areas were observed. An enhancement of similar to100% was observed when 60 mM Fe3+ replaced high concentrations of Hg2+. This method of convection exhibits promise for small-volume ASV analysis with possible improved limits of detection and decreased preconcentration times.

Journal
Analytical Chemistry
Volume
76
Issue
8
Year
2004
Start Page
2415
ISBN/ISSN
0003-2700
DOI
10.1021/ac0354490