Determination of minor element concentrations in reference materials

It has been shown, for a Pb isotopic reference material and for natural Cd, that total evaporation with integrating mass spectrometric measurement allows the determination of isotope ratios of these elements with sufficient accuracy and reproducibility. It is possible to use the method in carefully selected cases for IDA-TIMS measurements without the application of bias factors derived from isotopic reference material measurements. IDA-TIMS measurements were used for the determination of Cd (40–400 g/g) in polyethylene and Cd (10 g/g), Pb (500 g/g), Ga (150 g/g) and Zn (2000 g/g) in the Al alloy AlCuMg2. Relative standard deviations (n=5) were between 1.2% to 2.4% in the first case and 0.3% for Cd, 0.4% for Ga, 0.14% for Pb, 0.6% for Zn in the second. Deviations from the certified values were between 0.8% and 1.4% in the first case. The four concentration values contributed to the AlCuMg2 certification measurements but deviated from the finally certified values as follows: Cd+1.0%, Ga–1.6%, Pb–0.9% and Zn+10%.