title: MSFIA-LOV system for (226)Ra isolation and pre-concentration from water samples previous radiometric detection.
abstract: An automatic system based on multisyringe flow injection analysis (MSFIA) and lab-on-valve (LOV) flow techniques for separation and pre-concentration of (226)Ra from drinking and natural water samples has been developed. The analytical protocol combines two different procedures: the Ra adsorption on MnO2 and the BaSO4 co-precipitation, achieving more selectivity especially in water samples with low radium levels. Radium is adsorbed on MnO2 deposited on macroporous of bead cellulose. Then, it is eluted with hydroxylamine to transform insoluble MnO2 to soluble Mn(II) thus freeing Ra, which is then coprecipitated with BaSO4. The (226)Ra can be directly detected in off-line mode using a low background proportional counter (LBPC) or through a liquid scintillation counter (LSC), after performing an on-line coprecipitate dissolution. Thus, the versatility of the proposed system allows the selection of the radiometric detection technique depending on the detector availability or the required response efficiency (sample number vs. response time and limit of detection). The MSFIA-LOV system improves the precision (1.7% RSD), and the extraction frequency (up to 3 h(-1)). Besides, it has been satisfactorily applied to different types of water matrices (tap, mineral, well and sea water). The (226)Ra minimum detectable activities (LSC: 0.004 Bq L(-1); LBPC: 0.02 Bq L(-1)) attained by this system allow to reach the guidance values proposed by the relevant international agencies e.g. WHO, EPA and EC.
authors.affiliation: Environmental Radioactivity Laboratory (LaboRA), University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122, Palma, Spain; Environment and Energy Department, Advanced Materials Research Center (CIMAV) S.C., Miguel de Cervantes 120, Chihuahua, Chih. 31136, Mexico.
authors.forename: Rogelio
authors.initials: R
authors.lastname: Rodríguez
authors.affiliation: Environmental Radioactivity Laboratory (LaboRA), University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122, Palma, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Borràs
authors.affiliation: Environment and Energy Department, Advanced Materials Research Center (CIMAV) S.C., Miguel de Cervantes 120, Chihuahua, Chih. 31136, Mexico.
authors.forename: Luz
authors.initials: L
authors.lastname: Leal
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122, Palma, Spain.
authors.forename: Víctor
authors.initials: V
authors.lastname: Cerdà
authors.affiliation: Environmental Radioactivity Laboratory (LaboRA), University of the Balearic Islands, Cra. Valldemossa km 7.5, 07122, Palma, Spain. Electronic address: laura.ferrer@uib.es.
authors.forename: Laura
authors.initials: L
authors.lastname: Ferrer
mesh_terms: D011874:Radiometry / Q000379:methods*; D011883:Radium / Q000032:analysis / Q000302:isolation & purification*; D012588:Scintillation Counting; D014875:Water Pollutants, Radioactive / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D014875:Water Pollutants, Radioactive; D011883:Radium
keywords: (226)Ra; Automation; Flow analysis; Radiochemical analysis; Radiological water parameters