The uranium spectrophotometric measurement using the uranylnitrate-quaternaryamine solvent extraction method is investigated to identify factors that affect precision and accuracy of the uranium determination. The inherent spectrophotometric precision was measured with neutral density filters in the sample light path and was found to be <0.1% relative standard deviation (RSD). Under selected experimental conditions, temperature instability has a –0.02% effect on the extraction, and a –0.4% effect on the absorbance of the uranium extract in 2-nitropropane (2-NP) or methyl isobutyl ketone (MIBK) solvents. Under optimum conditions at the 10 mg uranium level, RSDs of 0.1% resulted.
We investigated the plutonium assay method that uses the plutonyl trinitrate tetrapropyl-ammonium ion-pair solvent extraction with spectrophotometry of the extract as a candidate method capable of providing robustness and precision. To identify and assess the effect of factors on the precision, we looked at sampling techniques, silver oxide oxidation conditions extraction time, extract stability, and temperature dependence of the extract analytical peak height and position. We obtained a precision of 0.12%.
Authors:J. Laul, M. Smith, C. Thomas, P. Jackson and N. Hubbard
Analytical procedures for measuring various radionuclides in the238U and232Th chains in briney waters are described. Using methods such as mass spectrometry, and alpha, beta and gamma spectrometry, the desired measurement sensitivity required for each of the radionuclides is achieved.233U,228Th,208Po,212Pb, and133Ba are used as tracers for chemical yield recoveries. Typical precision of the results range from 5–20%.