Characterization of calibration materials for trace element analysis and fingerprint studies of gold using LA-ICP-MS

Abstract

Two solid gold calibration materials were characterized in terms of element composition and distribution to investigate their applicability for fingerprint studies on Peruvian gold objects. The two calibration materials provide access to elements, which are important for archaeological investigations and fingerprint studies of gold objects. Furthermore, these calibration materials contain Ag as a major element, which provide matrix-matched calibration for the analysis of gold artifacts. The quantification of the potential calibration materials was carried out by LA-ICP-MS using solution calibration. The calibration solutions contained all necessary elements, which were prepared by transferring Ag into a chloro-complex and diluting the multi-element solutions with hydrochloric-acid in order to obtain stable element concentrations. The applicability of this calibration approach was validated by using NIST 8053 and NIST 8062 reference materials. The accuracy and precision were found to be better than 8% and 5%, respectively, for most of the determined elements. Investigations of selected Pre-Columbian gold artifacts showed the applicability of the produced gold calibration materials. The quantitative analyses for a wide range of elements of various gold artifacts contribute to further investigation of the provenance of gold types applied in the early Peruvian cultures.