Bismuth-coated carbon electrodes for anodic stripping voltammetry

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Mercury-film electrodes are common for stripping voltammetry but pose environmental and health risks.
• Developing mercury-free alternatives with comparable or superior performance is crucial for environmental and analytical applications.

Purpose of the Study:

• To evaluate the performance of in situ bismuth-film electrodes for stripping voltammetric determination of trace metals.
• To compare the capabilities of bismuth-film electrodes with traditional mercury electrodes.
• To explore the potential of bismuth-film electrodes as an environmentally friendly alternative.

Main Methods:

• In situ preparation of bismuth-film electrodes by adding bismuth(III) to the sample solution.
• Stripping voltammetry for the quantification of trace metals (Cd, Pb, Tl, Zn) at microgram per liter levels.
• Scanning electron microscopy (SEM) for characterizing bismuth deposit morphology.

Main Results:

• Bismuth-film electrodes demonstrated favorable stripping voltammetric performance, comparable to mercury electrodes.
• Well-defined peaks and low backgrounds were achieved for Cd, Pb, Tl, and Zn in non-deaerated solutions.
• Detection limits for lead as low as 0.3 ppb were obtained with short deposition times.
• Electrodes exhibited a wide potential window (-1.2 to -0.2 V), allowing for the quantitation of most metals measurable with mercury electrodes.
• High reproducibility was confirmed with low relative standard deviations for repetitive measurements.

Conclusions:

• In situ bismuth-film electrodes are a promising, environmentally friendly alternative to mercury electrodes for trace metal analysis.
• These electrodes offer sensitive, selective, and reproducible detection of various metals.
• Their performance and ease of use support their application in both centralized and decentralized testing settings.