Bismuth-coated screen-printed electrodes for stripping voltammetric measurements of trace lead

Bismuth-coated screen-printed carbon electrodes offer reliable quantitation of trace lead in connection to anodic stripping voltammetry. Such use of b ismuth films (instead of mercury coatings) does not affect the reliability of stripping measurements of trace lead. The influence of various experimen tal variables upon the stripping lead signal at the bismuth-coated thick-fi lm sensor is explored. The square-wave voltammetric stripping response is h ighly linear over the 10-100ppb lead range examined (2 min deposition), wit h a detection limit of 0.3 pph (10 min deposition) and good precision (RSD= 7.4% at 20ppb lead). The rapid square-wave stripping voltammetric mode faci litates the use of nondeaerated samples. Applicability to drinking water sa mples is demonstrated. The attractive behavior of the new disposable "mercu ry-free" carbon strip electrodes, coupled with the negligible toxicity of b ismuth, hold great promise for "one-shot" decentralized lead testing (inclu ding blood lead screening).