Search

A method for the isotope dilution mass spectrometric (IDMS) determination of boron in rye grass at the 5 µg · g-1 level has been developed. The mass spectrometric measurements are performed using negative thermal ionization at masses 42 (10B16O16O-) and 43 (11B16O16O-). The 10B/11B ratios are corrected for the 10B16O17O- contribution at mass 43 and for mass fractionation. The chemical blank is determined using the “standard addition” method. The numerical calculations are done with a least square fit computer program. The method has been applied for the certification of boron in BCR 281 (Rye Grass). The boron content of this reference material has been established as (5.64±0.56) µg·g-1.

Summary Any mass spectrometric measurement system has inherent inaccuracies caused by isotope fractionation in the ion source and non-linearity of the detector and or measurement system. A set of well known triple isotope mixtures is an excellent means to verify and correct non-linearity of the mass spectrometer detector and measurement system after the isotope fractionation has been corrected for. CBNM IRM 072/1-15 is a set of such mixtures. Its preparation and characterization is described. It is available for interested users.