Production and Certification of the Reference Material GSB 04‐3258‐2015 as a ¹⁴³Nd/¹⁴⁴Nd Isotope Ratio Reference

A new certified reference material, labelled GSB 04‐3258‐2015, for use as a 143 Nd/ 144 Nd isotope ratio reference has been prepared by the Institute of Geology, Chinese Academy of Geological Sciences, Beijing. Standardization Administration of the People's Republic of China provided the certification for this reference material. This report presents the reference 143 Nd/ 144 Nd isotope ratio and supporting production and certification procedures. The reference value was determined by an interlaboratory comparison of results from eleven participating laboratories using MC ‐ TIMS or MC ‐ ICP ‐ MS . The calibration of mass fractionation was conducted by using the exponential law, and the 143 Nd/ 144 Nd isotope ratios were normalised to the 146 Nd/ 144 Nd isotope ratio value of 0.7219. Isobaric interference of 144 Sm on 144 Nd was corrected using an interference‐free 147 Sm/ 149 Sm isotope ratio value for mass fractionation. GSB 04‐3258‐2015 shows sufficient homogeneity and stability for use as an international isotopic reference material. The certified value was calculated from the unweighted means of the results submitted by the participating laboratories. The 143 Nd/ 144 Nd isotope ratio value for GSB 04‐3258‐2015 is 0.512438, with a combined expanded uncertainty ( k = 2) of 5 × 10 −6 . Reference material GSB 04‐3258‐2015 is available upon request from the Institute of Geology, Chinese Academy of Geological Sciences, and may be used for accurate interlaboratory calibration of Nd isotope analysis.