PRECONCENTRATION OF TRACES OF AG, AU, BI, CU, AND PD FROM PURE LEAD BY PARTIAL PRECIPITATION OF THE MATRIX WITH NABH4 AS A REDUCING AGENT

Selected groups of trace elements can be preconcentrated from different materials by precipitation of a small amount of the matrix with NaBH4 as a reducing agent. The metallic precipitate serves as a trace collector for all elements being electrochemically nobler than the matrix. As an example for this technique traces of Ag, Au, Bi, Cu, and Pd are enriched from samples of 10 g pure lead and, after dissolving the collector in acid, determined by flame atomic absorption spectrometry. With trace contents of a few μg/g relative standard deviations of about 5 % are achieved. Depending on the element, the limit of detection was found to be between 0.05 and 0.4 μg/g. The accuracy of the analytical procedure was verified by use of analysed reference samples. © 1979 Springer-Verlag.