Analysis of ²¹⁰Pb in water samples with plastic scintillation resins

²¹⁰Pb is a radioactive lead isotope present in the environment as member of the ²³⁸U decay chain. Since it is a relatively long-lived radionuclide (T_1/2 = 22.2 years), its analysis is of interest in radiation protection and the geochronology of sediments and artwork. Here, we present a method for analysing ²¹⁰Pb using plastic scintillation resins (PSresins) packaged in solid-phase extraction columns (SPE cartridge). The advantages of this method are its selectivity, the low limit of detection, as well as reductions in the amount of time and reagents required for analysis and the quantity of waste generated. The PSresins used in this study were composed of a selective extractant (4′,4″(5″)-Di-tert-butyldicyclohexano-18-crown-6 in 1-octanol) covering the surface of plastic scintillation microspheres. Once the amount of extractant (1:1/4) and medium of separation (2 M HNO₃) were optimised, PSresins in SPE cartridges were calibrated with a standard solution of ²¹⁰Pb. ²¹⁰Pb could be fully separated from its daughters, ²¹⁰Bi and ²¹⁰Po, with a recovery value of 91(3)% and detection efficiency of 44(3)%. Three spiked water samples (one underground and two river water samples) were analysed in triplicates with deviations lower than 10%, demonstrating the validity of the PS resin method for ²¹⁰Pb analysis.