Clark Emily A, Fritsch Ingrid
Anal Chem. 2004 Apr 15;76(8):2415-8. doi: 10.1021/ac0354490.
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 Hg(2+) 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 Hg(2+) 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 approximately 100% was observed when 60 mM Fe(3+) replaced high concentrations of Hg(2+). This method of convection exhibits promise for small-volume ASV analysis with possible improved limits of detection and decreased preconcentration times.
研究了外部磁场对玻碳电极上汞膜中浓度为10⁻⁶ - 10⁻⁷ M的铅、镉和铜溶液中线性扫描阳极溶出伏安法（ASV）的影响。向分析物溶液中加入高浓度的Hg²⁺，以便在沉积步骤中产生大的阴极电流。因此，由于磁流体动力学，通过磁场的净电荷通量产生了大的洛伦兹力，从而导致对流。沉积过程中分析物更快地输送到汞膜电极导致阳极溶出峰增加。研究了不同Hg²⁺浓度（0 - 60 mM）和磁场强度（0 - 1.77 T）对溶出峰增强的影响。观察到峰电流增强高达129%，峰面积增强高达167%。当60 mM Fe³⁺替代高浓度的Hg²⁺时，观察到增强约100%。这种对流方法有望用于小体积ASV分析，可能改善检测限并缩短预浓缩时间。
