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

A neodymium oxide with relative Nd-143/Nd-144 ratio 1.000503 +/- 1(1 sigma( m)) to LaJolla Nd was prepared as a new isotopic reference. The neodymium r eagent was selected from two points of view as follows. The first is low ab undance of neighboring elements Ce and Sm, which affects isobaric interfere nce. The second is high Nd-143/Nd-144 ratio, which is closer to those of ch ondritic and mantle-derived materials. The Nd-143/Nd-144 ratio of the reage nt was measured alternately with LaJolla Nd to get a coherency with LaJolla Nd using 12 mass spectrometers in ii laboratories in Japan. Aliquots of th is neodymium oxide reagent named JNdi-1 are available upon request from the Geological Survey of Japan and may be useful for precise interlaboratory c alibration of Nd isotopes. (C) 2000 Elsevier Science B.V. All rights reserv ed.