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

Abstract

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 (2σ) of the ¹⁴³Nd/¹⁴⁴Nd ratio is less than 10 ppm (internal) and 20 ppm (external), respectively.

Keywords:

• Certified reference materials
• Chemical separation
• Multiple collector inductively coupled plasma mass spectrometry
• Neodymium isotope

Acknowledgments

We gratefully acknowledge Chaofeng Li, Zhuyin Chu, and Jianfeng Gao for constructive discussion and suggestion. We also thank Larry Ball (Thermo Fisher Scientific) for help with the English wording. Constructive comments of anonymous reviewers much improved the final draft. This work was financially supported by the Natural Science Foundation of China (Grants No. 40634019 and 40773008).

Notes

^a Measurement at May 8, 2008

^b Measurement at May 16, 2008

^c Determination purified Nd fraction by TIMS

^d Raczek et al. 2003

^e Weis et al. 2006

^f Li et al. 2007

^g Shibata et al. 2003

^h Qi and Zhou 2008

ⁱ Weis et al. 2005

^j Pin and Zalduegui 1997

^k Pin et al. 1994

^l Miyazaki and Shuto 1998

^m Nohda and Wasserburg 1998

ⁿ Orihashi et al. 1998.