Reference materials for geochemical studies: New analytical data by ICP-MSand critical discussion of reference values

Abundances of twenty four trace elements, including Y and fourteen rare ear th elements (REE), are reported for eighty six geological reference materia ls and four proficiency testing samples. Analytical data were obtained by I CP-MS using solution nebulisation after mixed acid digestion (HF-HClO4) und er pressure. Analysed samples cover a wide range of element concentrations and mineralogical compositions, including samples for which there are few p reviously published data. Precision for elemental determinations in nearly 90% of the samples analysed is better than +/- 5%. Accuracy, estimated by c omparison with data from compilations is better than +/- 6% for well charac terized reference materials. Results obtained for samples that are low in t race elements are often significantly lower than compiled reference values. A critical discussion of the compiled data sets, especially for Y and the REEs, indicates that some reference values seem to be erroneous.