Inter-element effects in the determination of trace amounts of plutonium by high resolution inductively coupled plasma atomic emission spectrometry

摘要

An analytical method was developed for the determination of plutonium (Pu) in aqueous solutions using high resolution inductively coupled plasma atomic emission spectrometry (ICP-AES). The analytical range for Pu in aqueous solution was 0.1 to 100 μg/mL. The validity of the method was established by analysis of several synthetic samples of plutonium. Plutonium was estimated in synthetic samples in the presence of uranium, thorium, rare earths, and common metallic elements after applying inter-elemental correction factors for the interfering elements. Radiometric methods were employed for an independent cross-check of the values obtained by ICP-AES. The results obtained by ICP-AES and the radiometric method were in good agreement with a precision of 10 to 20% at very low concentrations of Pu and better than 5% at higher concentration levels. The method is useful for the determination of Pu in different types of aqueous waste solutions generated in radiochemical laboratories, and also to monitor the trace levels of Pu left in the raffinate after its chemical separation along with other metallic constituents. It should be noted that the presence of large amounts of Pu in the raffinate can lead to an over-estimate in measured concentrations of the analytes of interest due to its rich emission spectrum.