Determination of traces of uranium and thorium in (Ba, Sr)TiO3 ferroelectrics by inductively coupled plasma mass spectrometry

• Published in: Analytical and bioanalytical chemistry 1997-03, Vol.357 (6), p.647-651
• Main Authors: FUKUDA, M, SAYAMA, Y
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Anion exchanging; Atomic beam spectroscopy; Barium; Chemistry; Detection limits; Emission analysis; Emission spectroscopy; Exact sciences and technology; Ferroelectric materials; Ferroelectricity; Hydrogen peroxide; Inductively coupled plasma mass spectrometry; Ions; Leaching; Mass spectrometry; Mass spectroscopy; Scientific imaging; Separation; Spectrometric and optical methods; Strontium; Thorium; Ultrasonic testing; Uranium
• ISSN: 0937-0633; 1618-2642; 1432-1130; 1618-2650
• DOI: 10.1007/s002160050228

Traces of uranium and thorium in barium(II), strontium(II) titanate ((Ba, Sr)TiO3) ferroelectric materials were determined by inductively coupled plasma mass spectrometry (ICP-MS). Samples were completely dissolved by a mixture of 1.4% H2O2 and 1.0 mol⋅l-1 HNO3. For a complete separation of the analytes from the matrix elements, a two step separation technique involving leaching and anion-exchange was applied. By the leaching step with HNO3 more than 90% of the matrix can be removed whereas the analytes completely remained in the solution. The anion-exchange step was carried out on a BIO⋅RAD AG1-X8 column with a mixture of 1.0 mol⋅l-1 HF and 0.5 mol⋅l-1 HNO3 as eluent. The content of uranium and thorium was subsequently measured by ICP-MS. The detection limits (D.L.) obtained were 0.043 ng g-1 and 0.035 ng g-1 for U and Th, respectively. The reproducibility was satisfactory with a relative standard deviation of less than 3% (at the 1 ng g-1 level, n=5). The matrix concentrations in the final solution were reduced to the sub-μg ml-1 level which is in the range of the detection limits of USN-ICP-AES (ultrasonic nebulization-ICP-atomic emission spectroscopy). The method was successfully applied to the determination of uranium and thorium in three synthetic (Ba, Sr)TiO3 samples spiked with the analytes at levels of 1, 5 and 10 ng g-1 and three (Ba, Sr)TiO3 ferroelectric samples containing sub-ng g-1 levels of the analytes.