Development and refinement of approaches for the determination of isotope ratios and elemental ratios in skeletal tissue, leading to a reduction of the risk of misinterpretation of such data. Capabilities of several types of ICP-MS instrumentation will be compared. The possibility of using laser ablation for direct bulk and spatially resolved analysis of solid bone will be evaluated. All efforts aim at unraveling provenance of human remains and reconstruction of past human mobility and diet.