Anodic Stripping Voltammetry with Galinstan as Working Electrode

The liquid alloy galinstan is used to determine low concentrations in microgram per liter level of trace metals like copper, cadmium, lead, bismuth, antimony and thallium using anodic stripping voltammetry. Like the conventionally applied HMDE, the hanging galinstan drop electrode (HGDE) is able to accumulate the investigated metal ions at the electrode surface. Hence, simultaneous determination of Pb and Cd is possible. Both, DPASV and SWASV were used as measuring methods. The influence of different parameters like accumulation potential and time and the frequency in SWASV were studied. By the use of acetic buffer solutions, the potential window reaches from ?900 mV to 150 mV. The limit of detection (LOD) varies from 6 ppm (worst case, Sb³⁺) to 2 ppb (best case, Pb²⁺). Therefore, the use of galinstan in the form of the HGDE is possible as a “mercury‐free” and environmentally friendly electrode in stripping analysis.