A comparison study on the use of Dowex 1 and TEVA-resin in determination of ⁹⁹Tc in environmental and nuclear coolant samples in a SIA system with ICP-MS detection

This work refers to a comparative study of sorbents widely used in determinations of ⁹⁹Tc such as TEVA resin and Dowex 1. Despite having a similar functional group of quaternary amines, both materials represent different chromatographic methods-extraction (TEVA resin) and anion exchange (Dowex 1)-which provides a diverse range of their properties significant in determination of ⁹⁹Tc in flow conditions. The comparative tests, carried out in a SIA-LOV (Sequential Injection Analysis-Lab-on-Valve) system combined with mass spectrometric (ICP-MS) detection, considered several factors that are crucial from the standpoint of resin´s utility such as sorption capacity, durability, or selectivity, critical in ⁹⁹Tc separation from interferences. The developed and optimized analytical procedure based on the application of the TEVA resin provided determinations of ⁹⁹Tc at minimum detectable limit (MDL) 6.00 mBq L^-1 in 50 min and has been successfully employed in analyses of samples from nuclear industrial and research units (reactor coolant and sewage) as well as from the river surrounding the nuclear reactor. The method proved to be sufficient for routine analysis of water samples in accordance with EPA standards. The reliability of the method was confirmed in the analysis of the BH standard provided by the NPL for inter-laboratory proficiency tests. The ⁹⁹Tc recovery for all real samples was evaluated as 80-100%.