Improved approach for the determination of low-Z elements in uranium samples using a vacuum chamber TXRF spectrometer

摘要

Total reflection X-ray fluorescence (TXRF) method for the determination of low atomic number (Z) elements Na (Z = 11) to Ca (Z = 20) using Cr K alpha excitation, vacuum atmosphere sample chamber, and ultrathin window detector of a low Z-high Z TXRF spectrometer has been developed. The earlier reported problem in determination of Al, due to interference of U M alpha escape peak with Al Ka, was taken care by more intense solvent extraction-based separation of uranium matrix from the sample solutions. Any dissolved tri-n-butyl phosphate having traces of uranium left after solvent extraction was removed from the sample solutions by equilibrating with n-dodecane. This approach resulted in the betterment of analytical results. The method developed was validated by analyzing three Certified Reference Materials for trace metals in uranium oxide, developed by Department of Atomic Energy, Government of India. The TXRF determined results were found to have an average precision of 8.0% (1 sigma, n = 3) and the average deviation of the TXRF determined values from the certified concentrations was 7.3%. Copyright (C) 2017 John Wiley & Sons, Ltd.