Determination of Th Isotopes (²³²Th, ²³⁰Th and ²²⁸Th) in Titanium Ore Certified Reference Material by Alpha-ray Spectrometry

Abstract

An analytical method using alpha-ray spectrometry of Th isotopes was developed for the determination of ²³²Th, ²³⁰Th and ²²⁸Th in National Institute of Standards and Technology titanium ore certified reference material NIST SRM 670 Rutile. After fusing by Na₂O₂ and NaOH, hydroxide precipitation, coprecipitation with yttrium oxalate, and anion-exchange chromatography were applied to the analysis. The analytical results of Th isotopes in NIST SRM 670 were in agreement with the determined values measured by INAA (instrumental neutron activation analysis). It was found that the proposed method could be applied for determination of Th isotopes in titanium-rich samples, for example, titanium ore.