Determination of Total Germanium in Chinese Herbal Remedies by Square-Wave Catalytic Adsorptive Cathodic Stripping Voltammetry at an Improved Bismuth Film Electrode

Figure 1

Square-wave stripping voltammograms recorded at the improved BiFE plated in 1 mol L⁻¹ acetate buffer (pH 4.5) containing 0.08 mol/L trisodium citrate (a, b, and d) and the BiFE (c) plated in 1 mol/L acetate buffer (pH 4.5) without trisodium citrate: (a) 0.1 mol L⁻¹ HAc-NaAc (pH 4.8) + pyrogallol (1.3×10⁻³ mol L⁻¹); (b) a + 10 μg L⁻¹ Ge(IV); (c, d) b + 2×10⁻⁴ mol L⁻¹ KBrO₃; deposition potential: −0.34 V; deposition time: 150 s; SW frequency: 25 Hz; scan increment: 4 mV; pulse height: 50 mV.