STRIPPING VOLTAMMETRY AT MICRODISK COMPOSITE ELECTRODE ASSEMBLY

The attractive stripping voltammetric performance of the recently deve loped RAM electrode, consisting of 3.5-mu m radius carbon microdisks e mbedded in epoxy resin, is described. The microdisk dimensions and int erdisk spacings of the RAM surface lead to nonlinear diffusional flux and offer efficient metal deposition from quiescent samples. Coupled w ith large ''collective'' stripping currents, a wide potential window a nd a low background current, the new electrode yields low detection li mit (e.g., 0.3 mu g/L lead and cadmium for 2-min deposition) and good precision (2.1-2.3% RSD, n = 15). Assays of drinking water are used fo r illustration.