Detection of radium at the attogram per gram level in copper by inductively coupled plasma mass spectrometry after cation-exchange chromatography
In this study, a new method was developed for the separation and isolation of radium from metallic copper. Radium was separated from matrix constituents and possible impurities using an AG50W-X8 cationic resin and a series of specific-pH eluants containing complexing ligands. An instrumental detection limit of 2 mBq L−1 (53 fg L−1) and a quantification limit of 6 mBq L−1 (175 fg L−1) were achieved when the separation method was coupled with ICP-MS. The limits of detection and quantification for the new method translate into 0.3 μBq g−1 (9 ag g−1) and 1 μBq g−1 (28 ag g−1), respectively, for a 100 g sample treated by leaching. This method can be used to measure radium content at the ultratrace level in copper to be used in the fabrication of sensitive radiation detectors.