title: Ultratrace-level radium-226 determination in seawater samples by isotope dilution inductively coupled plasma mass spectrometry.
abstract: An improved and novel sample preparation method for 226Ra determination in liquid samples by isotope dilution inductively coupled plasma sector field mass spectrometry using laboratory-prepared 228Ra tracer has been developed. The procedure involves a selective preconcentration achieved by applying laboratory-prepared MnO2 resin followed by cation exchange chromatographic separation. In order to completely eliminate possible molecular interferences, medium mass resolution (R = 4,000) combined with chemical separation was found to be a good compromise that enhanced the reliability of the method. The detection limit of 0.084 fg g(-1) (3.1 mBq kg(-1)) achieved is comparable to that of the emanation method or alpha spectrometry and is suitable for low-level environmental measurements. The chemical recovery of the sample preparation method ranged from 72 to 94%. The proposed method enables a rapid, accurate and less labor-intensive approach to routine environmental 226Ra determination than the radioanalytical techniques conventionally applied.
authors.affiliation: Radiation Safety Department, Institute of Isotopes, Hungarian Academy of Sciences, Konkoly-Thege utca 29-33, 1121, Budapest, Hungary. varga@iki.kfki.hu
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Varga