JNdi-1 : a neodymium isotopic reference in consistency with LaJolla neodymium

Abstract A neodymium oxide with relative 143 Nd/ 144 Nd ratio 1.000503±1(1 σ m ) to LaJolla Nd was prepared as a new isotopic reference. The neodymium reagent was selected from two points of view as follows. The first is low abundance of neighboring elements Ce and Sm, which affects isobaric interference. The second is high 143 Nd/ 144 Nd ratio, which is closer to those of chondritic and mantle-derived materials. The 143 Nd/ 144 Nd ratio of the reagent was measured alternately with LaJolla Nd to get a coherency with LaJolla Nd using 12 mass spectrometers in 11 laboratories in Japan. Aliquots of this neodymium oxide reagent named JNdi-1 are available upon request from the Geological Survey of Japan and may be useful for precise interlaboratory calibration of Nd isotopes.