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 MnO(2), deposited on cotton fiber, is eluted with hydroxylamine and subsequently coprecipitated with BaSO(4). (226)Ra activity is determined off-line by using a low background proportional counter. The procedure yield is (90+/-3)% and its lower limit of detection 0.05BqL(-1). This method has been applied satisfactorily to different types of spiked water (tap, mineral and seawater).