Preliminary Results in Gold Provenance Characterization using LA ICP MS (Resultados preliminares na caracterização da proveniência de ouro usando LA ICP MS)

We present some preliminary results of Pb isotopes characterization of gold samples.The first  aim of this work is to apply an archeometry technique, that is, geographical origin characterization of ancient artifacts in order  to characterize gold provenance. Using Pb isotopes in gold samples in which that metal is found as a trace is possible using ICP MS techniques. In this work was also used laser ablation to extract material from the sample.Samples have been obtained from three brazilian geographically distinct gold-digging sites. The samples were processed only by fusion into a furnace at 1,200 oC. Laser ablation and analysis by aa ICP MS was performed. We have measured Pb isotopes at ppb levels and have derived a few relations among them and made some graphics. In those graphics one can see the measured relations are characteristic fingerprints of each single site. Therefore, the pure gold provenance can be quite well characterized using mass spectrometry instrumentation and its techniques. Further work is in progress to determine the behaviour of mixed gold samples from different provenances. Besides that, measurements with different  sample preparation will be made, in order to compare results with laser ablation extraction.