Development of disposable bulk-modified screen-printed electrode based on bismuth oxide for stripping chronopotentiometric analysis of lead (II) and cadmium (II) in soil and water samples

A bulk-modified screen-printed carbon electrode characterised for metal ion detection is presented. Bismuth oxide (Bi2O3) was mixed with graphite-carbon ink to obtain the modified electrode. The best composition was 2% Bi2O3 (wt%) in the graphite-carbon ink. The modified electrode with onboard screen-printed carbon counter and silver–silver chloride pseudo-reference electrodes exhibited good performance in the electrochemical measurement of lead (II) and cadmium (II). The electrode displayed excellent linear behaviour in the concentration range examined (20–300 μg L−1) with limits of detection of 8 and 16 μg L−1 for both lead (II) and cadmium (II), respectively. The analytical utility of the modified electrode was illustrated by the stripping chronopotentiometric determinations of lead (II) in soil extracts and wastewater samples.