Lead isotope analysis of archaeological metals by multiple-collector inductively coupled plasma mass spectrometry

Lead isotope ratios in archaeological silver and copper were determined by MC-ICPMS using laser ablation and bulk dissolution without lead purification. Laser ablation results on high-lead metals and bulk solution analyses on all samples agree within error of TIMS data, suggesting that problems from isobaric interferences and/or mass bias variations due to the presence of matrix elements are insignificant. Inaccurate laser ablation analyses on low-lead copper reflect erroneous mass bias corrections from use of a non-matrix matched standard. However, in most cases, silver and copper are analysable for lead isotopes by bulk dissolution or laser ablation MC-ICPMS with simplified sample preparation.