Interlaboratory Comparison for Boron Isotope Ratio Measurement with Inductively Coupled Plasma – Quadrupole Mass Spectrometer

Boron isotope ratios were analyzed in seven domestic analytical labs for boric acid solutions with various compositions of boron isotope abundances, using an Inductively Coupled Plasma–Quadrupole Mass Spectrometer (ICP-QMS). Five sample solutions with different isotope abundances of 10B were prepared in the range of 10 to 20% by mixing two boric acid solutions containing natural B and enriched 11B, respectively. Then, the 10B isotope abundances of each sample were certified by analyzing with thermal ionization mass spectrometry (TI-MS) according to ASTM-C791-04. Results obtained from each lab have indicated good coincidences with TI-MS results. Also, the relative standard deviations of results with ICP-QMS of seven analytical labs were 0.11 to 0.81%. The measurement precision for ICP-QMS would be sufficient in terms of practical use, while taking into consideration a valid requirement required for verifying a depletion of the 10B isotope abundance in the PWR coolant, while this is greater than a nominal analytical error (relative value : 0.22%) for TI-MS shown in ASTM-C791-04.