Final report on key comparison CCQM-K8 of monoelemental calibration solutions

Abstract

This report describes a key comparison of monoelemental calibration solutions, organized under the auspices of the Consultative Committee for Amount of Substance (CCQM) in 1999-2000 and piloted by the Federal Laboratories for Materials Testing and Research (EMPA, Switzerland) and the Laboratoire National d'Essais (BNM-LNE, France). Solutions of aluminium, copper, magnesium and iron were measured. Although different methods of measurement were applied, most of the thirteen participating national metrology institutes achieved results within the required target range for a combined standard uncertainty of 0.5 % relative for each element. The methods used were titrimetry, coulometry, gravimetry, isotope dilution mass spectrometry and inductive coupled plasma/emission spectrometry.

The Status of Radiation Damage Experiments

“…The rapid expansion in the pyrochlore ceramic and the rate at which it is rendered amorphous is surprising. From the literature, it was anticipated that pyrochlore and zirconolite would become amorphous at about the same rate (Weber and, although our results indicate that this is highly dependent on composition.…”

Preparation and characterization of primary magnesium mixtures for the ab initio calibration of absolute magnesium isotope ratio measurements

“…33 In the case of Mg the smallest relative expanded uncertainty being published is 0.018% and relates to the primary solution used for the CCQM key comparison K8. 42 Thus the primary solutions of the isotopically enriched Mg materials produced in this project are unsurpassed in their expanded uncertainty. From these primary solutions the synthetic isotope mixtures were prepared offering relative expanded uncertainties for the mass ratios between 0.0058% and 0.0069%, which has not been achieved before.…”

The New Measurement Concept Explained by Using an Introductory Example

“…In this way, the measurement is decoupled from the true value and comparability between laboratories can be achieved at least if the same analytical procedure is used and even in many cases if different procedures are used. The latter has been demonstrated several times in key comparisons by metrological laboratories, for example, for the determination of cholesterol in human serum (18), for the determination of Al, Cu, Mg, and Fe in monoelemental calibration solutions (19), or for the determination of cadmium in rice (20). Sometimes, a closer standardization of the analytical procedure may be necessary to achieve comparability within a given measurement uncertainty.…”