New ID-TIMS, ICP-MS and SIMS data on the trace element composition and homogeneity of NIST certified reference material SRM 610-611

We present new concentration data for twenty four lithophile trace elements in NIST certified reference material glasses SRM 610-SRM 611 in support of their use in microanalytical techniques. The data were obtained by solutio n ICP-MS and isotope dilution TIMS analysis of two different sample wafers. An overall assessment of these new results, also taking into account ion p robe studies that have been published in the literature, shows that these w afers can be considered to be homogeneous. Therefore, individually analysed wafers are believed to be representative of the entire batch of the SRM 61 0-611 glasses. Possible exceptions are the alkali metals (and a few volatil e or non-lithophile trace elements). The analysed concentrations range betw een 370 mug g(-1) (Cs) and 500 mug g(-1) (Sr) and agree well with published values. On the basis of our new data and data recently published in the li terature we propose "preferred average" values for the elements studied. Th ese values are, within a few percent, identical to those proposed by other workers.