Abstract: Anodic stripping voltammetry (ASV) employing mercury-film electrodes (MFEs) has been widely adopted as a standard technique for trace cadmium detection and incorporated into undergraduate laboratory programs. However, conventional MFEs present significant drawbacks including mercury contamination risks and poor reproducibility, along with excessive cadmium consumption during experiments. In this study, we developed an innovative mercury-free electrode utilizing a composite material of low-toxicity eutectic gallium-indium (EGaIn) alloy and electrochemically reduced graphene oxide (erGO). By implementing square-wave voltammetry instead of linear sweep voltammetry, an improved protocol for trace cadmium determination was established. Experimental results demonstrated substantial enhancements in signal stability and sensitivity. Notably, the modified method reduced cadmium consumption by over two orders of magnitude while decreasing experimental costs by approximately 50%, showcasing its environmental and economic advantages. This redesigned experiment integrates multidisciplinary concepts from analytical chemistry, materials science, and physical chemistry, addressing contemporary environmental concerns while providing a safer, cost-effective alternative. The approach not only enhances students’ practical skills but also fosters research interest and innovative thinking in electroanalytical chemistry, making it highly suitable for undergraduate laboratory education.

Key words: Instrumental analysis, Anodic stripping voltammetry, Cadmium ion detection, Laboratory teaching