Development of an MSFIA-MPFS pre-treatment method for radium determination in water samples

A new automatic method for preconcentration and separation of radium in water samples has been developed. Such method combines both multisyringe (MSFIA) and multi-pumping (MPFS) flow analysis techniques allowing to analyze larger sample volumes with a higher throughput than other previous methodologies. Ra adsorbed on MnO2, deposited on cotton fiber, is eluted with hydroxylamine and subsequently coprecipitated with BaSO4. 226Ra activity is determined off-line by using a low background proportional counter. The procedure yield is (90 ± 3)% and its lower limit of detection 0.05 Bq L−1. This method has been applied satisfactorily to different types of spiked water (tap, mineral and seawater).