The analysis of <scp> ²²⁶ Ra </scp> in 1‐liter seawater by isotope dilution via single‐collector sector‐field <scp>ICP‐MS</scp>

The precise determination of radium‐226 (226Ra) in environmental samples is challenging due to its low concentration. Seawater typically contains between 0.03 and 0.1 fg g−1 226Ra. Thus, this work addresses the need for an easy methodology 226Ra seawater that may be applied routinely a large number samples. For reason, new analytical approach has been developed quantification via inductively coupled plasma mass spectrometry (ICP‐MS). Analysis by single collector sector‐field ICP‐MS was shown convenient reliable purpose once potential molecular interferences were excluded combination chemical separation intermediate resolution analysis. proposed method allows purification Ra from sample matrix based on preconcentration MnO2 precipitation, followed two‐column using cation exchange resin extraction chromatographic resin. can acidified unacidified recovery efficiency ranged 90% 99.8%, with precision 5%, accuracy 95.7% 99.9%, detection limit 0.033 fg g−1 (referring original concentration seawater). measure concentrations North Sea validated analyzing central Arctic (GEOTRACES GN04). Samples crossover station (from GEOTRACES GN04 GN01 research cruises) analyzed alternative methods, our results are good agreement published values.