In situ electrochemical detection of trace metal vapors at bismuth doped carbon screen printed electrodes

Volatile species of Pb, Cd and Zn were generated at room temperature by the addition of sodium tetrahydroborate(III) to an acidified solution of the analytes. The vapor-phase species were quickly adsorbed into a thin layer of highly porous hydrogel which was dip-coated on screen printed electrode for electrochemical detection using square wave anodic stripping voltammetric method. The square wave voltammetric stripping response is highly linear over the 10-80 ng range of Pb, Cd and Zn examined (2 min deposition), with a detection limit of 1 ng and good precision (RSD 7.4%). The attractive behavior of the new disposable carbon strip electrodes hold great promise for a simple, rapid, sensitive on-site real-time detection of trace metal vapors.