IN‐SITU ELEMENTAL AND Sr ISOTOPE INVESTIGATION OF HUMAN TOOTH ENAMEL BY LASER ABLATION‐(MC)‐ICP‐MS: SUCCESSES AND PITFALLS*

Trace element and Sr isotope data were obtained by laser ablation‐ and solution mode‐(MC)‐ICP‐MS analysis for tooth enamel from remains excavated at the New Kingdom period Egyptian colonial and Nubian cemetery site of Tombos (Sudan). Elemental abundances determined by both methods of ICP‐MS analysis yielded comparable values; however, 87 Sr/ 86 Sr values obtained by laser ablation were higher compared to their solution mode counterparts. This discrepancy is related to the production of a molecular interference—Ca + P + O (overlaps 87 Sr); hence the higher 87 Sr/ 86 Sr values recorded during ablation analyses. Laser ablation studies of enamel may provide relatively precise 87 Sr/ 86 Sr values rather quickly but cannot be used for accurately deciphering historical population migrations.