High-Precision Measurements of the 143Nd/144Nd Isotope Ratio in Certified Reference Materials without Nd and Sm Separation by Multiple Collector Inductively Coupled Plasma Mass Spectrometry

摘要

We present a precise and accurate method for the determination of 143Nd/144Nd isotope ratio without Nd and Sm separation by multiple collector inductively coupled plasma mass spectrometry. We corrected instrumental mass discrimination by applying the natural constant 146Nd/144Nd ratio as an internal standard after isobaric interference correction of 144Sm on 144Nd using interference-free 147Sm/149Sm ratio for Sm mass fractionation. The present method was validated by duplicate analyses of several certified reference materials after dissolution and cation-exchange resin purification. The precision (2 sigma) of the 143Nd/144Nd ratio is less than 10ppm (internal) and 20ppm (external), respectively.