title: Pre-concentration of naturally occurring radionuclides and the determination of (212)Pb from fresh waters.
abstract: A novel technique has been developed for determining the (212)Pb activity of fresh waters. This is of interest to environmental monitoring programmes that utilise gross α-activity methods to screen for anthropogenic radionuclides. The contribution from (212)Pb varies, and is difficult to experimentally measure due to its relatively short half-life (t(½) = 10.6 h) and low environmental activity (<0.1 Bq l(-1)). The use of a three-stage technique that encompasses a unique form of pre-concentration, separation and analysis by liquid scintillation counting allows a lower detection limit of 0.006 Bq l(-1) with a chemical yield of 92.5 ± 5.6%. The measurement can be obtained within 7 h of sample collection, and is calculated using the radioactive decay of (212)Bi. Other naturally occurring radionuclides may also be extracted using the pre-concentration stage of the technique, with efficiencies above 90% at a range of pH values.
authors.affiliation: Atomic Weapons Establishment, Aldermaston, Reading, Berkshire RG7 4PR, UK. jonathan.burnett@awe.co.uk
authors.forename: J L
authors.initials: JL
authors.lastname: Burnett
authors.forename: I W
authors.initials: IW
authors.lastname: Croudace
authors.forename: P E
authors.initials: PE
authors.lastname: Warwick
mesh_terms: D001417:Background Radiation; D001729:Bismuth / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry*; D007856:Lead Radioisotopes / Q000032:analysis*; D017895:Manganese Compounds; D010087:Oxides; D011834:Radiation Monitoring / Q000379:methods* / Q000706:statistics & numerical data; D012588:Scintillation Counting / Q000379:methods*
chemical_list: D007856:Lead Radioisotopes; D017895:Manganese Compounds; D010087:Oxides; C016552:manganese dioxide; D001729:Bismuth