An Assessment of the Suitability of NIST Glass SRM Literature Data for the Derivation of Reference Values

Abstract

The NIST certified reference materials, SRMs 610‐617, Trace Elements in Glass, are used extensively in geo‐analysis as microanalytical reference materials; however, present practice is not in keeping with ISO guidelines. One reason is that these samples were originally certified as bulk reference materials, and homogeneity conclusions based on test portion masses of about 0.5 g may differ significantly from those based on the much smaller mass relevant to microprobe analysis. Another is that certified values are not available for all elements of interest in micro‐analytical applications. In this manuscript, published homogeneity data is reviewed to show that these samples are suitable for use as microanalytical reference materials. In addition, an evaluation is undertaken of data quality requirements for micro‐analytical applications which shows that data contributing to existing compilations are insufficiently repeatable to detect bias between the individual contributed data and the compilation mean. Furthermore, existing published compilations do no yield reference data that is entirely “fit for purpose”, based on published criteria. To resolve these difficulties, it is proposed that a detailed measurement programme should be organised by the IAG with the intention of generating new data that would permit updating the certifications, and so greatly enhance current use of these glasses, and improve overall quality assurance in micro‐analytical laboratories based on appropriate microanalytical fitness for purpose criteria.

Evaluation of the Homogeneity of the Uranium Isotope Composition of NIST SRM 610/611 by MC-ICP-MS, MC-TIMS, and SIMS

“…Odd and even numbered glasses from the same series differ only in wafer size: 12 × 3 mm (even numbers) and 12 × 1 mm (odd numbers). Most elements are present in lower abundances than the nominal concentrations due to dilution by addition of the trace element mixture or loss during manufacturing [23][24][25]. Depletions in siderophile and chalcophile elements (likely lost to crucibles and/or the furnace), depletions in volatiles (in particular the alkali elements and boron), formation of 3D compositional cords during the caning process, and loss of elements from the glass surface have been observed [18,19,23,24].…”

GSD-1G and MPI-DING Reference Glasses for In Situ and Bulk Isotopic Determination

“…As outlined by Kane (1998) and Jochum et al. (2000), one of the most important drawbacks of the NIST glasses for the analysis of geological samples is that the glasses have major element compositions very different from geological materials.…”

Determination of Zr and Hf in a Flux‐Free Fusion of Whole Rock Samples using Laser Ablation Inductively Coupled Plasma‐Mass Spectrometry (LA‐ICP‐MS) with Isotope Dilution Calibration

“…Without isotope dilution, external calibration is often carried out using NIST SRM 612 or 610 despite the fact that this glass is not certified for microanalysis (Kane 1998). measured, removed the need for external calibration.…”