Journal article

Silver isotope analysis of gold nuggets: An appraisal of instrumental isotope fractionation effects and potential for high-resolution tracing of placer gold

Gerhard Bruegmann, Michael Brauns, Roland Maas

CHEMICAL GEOLOGY | ELSEVIER SCIENCE BV | Published : 2019

Abstract

We describe a technique for high-precision analysis of 109Ag/107Ag ratios in natural and archaeological gold (1.0–120 mg/g Ag) with particular emphasis on the control of Ag yield and effects of instrumental mass bias. After dissolution of mg-sized gold samples in aqua regia and conversion to chlorides, a miniature column filled with the anion exchange resin AG@1-X8 was used for removal of Au from the sample solutions. In a second miniature column made of the Triskem TBP resin Ag was converted from the chloride to the nitrate form. Isotopic analyses on the MC-ICP-MS employed the combination of Pd-doping and standard bracketing and considering the measurements of replicate dissolutions and chr..

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