A contribution to the problem of increasing fhe sensitivity of anodic-stripping voltammetry

A brief discussion of problems connected with increasing the sensitivity of anodic-stripping determinations is presented. A new microcell for anodic-stripping voltammetry in solution volumes down to about 0.01 ml was constructed. The effect of the solution volume, the mercury-drop electrode size, and of the pre-electrolysis time and potential on the sensitivity of determinations was studied and the reproducibility of results for determinations of lead in mineral acids is given. It was found that nanogram amounts of heavy metals can easily be determined in this way. In determination of 2 ng of Pb(2+) in 0.02 ml of solution the results were 2.00 +/- 0.13 ng (95% confidence limits), the mean relative deviation being 6.3%. For determination of copper in KNO(3), stripping microanalysis was compared with atomic-absorption spectrophotometry. Advantages and disadvantages of stripping voltammetry on the macro- and micro-scales are discussed.