Laser induced breakdown spectroscopic quantification of platinum group metals in simulated high level nuclear waste

LIBS has been developed for the quantification of platinum group metals (PGM), namely Pd, Rh and Ru in simulated high level liquid nuclear-waste (SHLLW) samples to provide an alternative analytical approach to other techniques. Calibration curves were obtained using high purity solutions of the individual PGMs and were validated using the individual PGM solutions as well as their mixtures. The amounts of the PGMs present in SHLLW both in the presence and in the absence of uranium were determined. The results agreed well with the expected values when the concentration of uranium was up to 700 ppmw, while positive bias was observed in the presence of larger amounts of uranium (above 700 ppmw). For such samples, satisfactory agreement of the results with those of the expected values was obtained after extraction of uranium with tributylphosphate.