Determination of lead(II) and cadmium(II) in water lily stems using a bismuth film electrode

Abstract

Mesoporous silica nanoparticles and chitosan were combined with ex-situ bismuth film modified glassy carbon electrode (NanoSiO2–CTS/BiFE) for simultaneous determination of Pb(II) and Cd(II) in HCl/KCl pH 2.2. Differential pulse anodic stripping voltammetry (DPASV) measurements, based on formation of ion-associates between chlorocomplexes and protonated amino groups (–NH3+) of chitosan at the electrode surface, were explored. Under optimum conditions, the linear correlation coefficient was 0.998 for both Pb(II) and Cd(II) after 240 s of deposition time. The limits of detection (LOD) and quantification (LOQ) were 1.0 mg/L and 3.3 mg/L for Pb(II) and 0.5 mg/L and 1.6 mg/L for Cd(II), respectively. The method exhibited satisfactory reproducibility and the results comparable to ICP-OES. Also, DPASV at NanoSiO2–CTS/BiFE was applied successfully in determining Pb(II) and Cd(II) in water lily stems in Thale Noi.