Analytical Methods for the Determination of 90Sr and 239,240Pu in Environmental Samples

Abstract

Artificial long-lived radionuclides such as 90Sr and 239,240Pu have been long released into the environment by human nuclear activities, which have a profound impact on the ecological environment. It is of great significance to monitor the concentration of these radionuclides for environmental safety. This paper summarizes and critically discusses the separation and measurement methods for ultra-trace determination of 90Sr, 239Pu, and 240Pu in the environment. After selecting the measurement method, it is necessary to consider the decontamination of the interference from matrix elements and the key elements, and this involves the choice of the separation method. Measurement methods include both radiometric methods and non-radiometric methods. Radiometric methods, including alpha spectroscopy, liquid scintillation spectrometry, etc., are commonly used methods for measuring 239+240Pu and 90Sr. Mass spectrometry, as the representative of non-radiometric measurement methods, has been regarded as the most promising analytical method due to its high absolute sensitivity, low detection limit, and relatively short sample-analysis time. Through the comparison of various measurement methods, the future development trend of radionuclide measurement is prospected in this review. The fully automatic and rapid analysis method is a highlight. The new mass spectrometer with ultra-high sensitivity shows strong analytical capabilities for extremely low concentrations of 90Sr, 239Pu, and 240Pu, and it is expected to develop determination methods with higher sensitivity and lower detection limit.

Scalable Dialysis-Based Method for the Isolation of Strontium from Milk for Radioanalysis

“…Further, some of the closest analogues to strontium in milk are present at a macroscale; according to global averages, calcium and magnesium concentrations in raw milk are 36,632 μM (1.47 g·L –1 ) and 4792 μM (0.116 g·L –1 ), respectively, while that of strontium is only 6.65 μM (0.58 mg·L –1 ) . To contend with such complexity, many methods have been described for both routine and emergency contexts. ,− Among these, solid-phase extraction figures prominently, particularly with the development of commercially available supports bearing chelating agents of high specificity . Being convenient, and hence potentially well-suited to emergency response, such substrates typically require a small sample size (≤100 mL) with a preconcentration step via extraction or precipitation, − while others adhere to sample ashing. …”