title: Quality control assurance of strontium-90 in foodstuffs by LSC.
abstract: A method based on the separation of Sr-90 by extraction chromatography and beta determination by Liquid Scintillation Counting (LSC) technique was used for strontium analysis in food samples. The methodology consisted in prior sample treatment (drying and incineration) followed by radiochemical separation of Sr-90 by extraction chromatography, using the Sr-resin. The chemical yield was determined by gravimetric method, adding stable strontium to the matrix. Beta activity (Sr-90/Y-90) was determined using a low background liquid scintillation spectrometer (Tri-Carb 3170 TR/SL, Packard). The accuracy and the precision of the method, was performed previously through recovery trials with Sr-90 spiked samples, using the same type of matrices (milk, complete meals, meat and vegetables). A reference material (IAEA_321) was now used to measure the accuracy of the procedure. Participation in interlaboratory comparison exercises was also performed in order to establish an external control on the measurements and to ensure the adequacy of the method.
authors.affiliation: Instituto Superior Técnico, Campus Tecnológico e Nuclear, Laboratório de Proteção e Segurança Radiológica, Estrada Nacional 10 (ao km 139,7), Bobadela LRS 2695-066, Portugal. Electronic address: ilopes@ctn.ist.utl.pt.
authors.forename: I
authors.initials: I
authors.lastname: Lopes
authors.affiliation: Instituto Superior Técnico, Campus Tecnológico e Nuclear, Laboratório de Proteção e Segurança Radiológica, Estrada Nacional 10 (ao km 139,7), Bobadela LRS 2695-066, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Mourato
authors.affiliation: Instituto Superior Técnico, Campus Tecnológico e Nuclear, Laboratório de Proteção e Segurança Radiológica, Estrada Nacional 10 (ao km 139,7), Bobadela LRS 2695-066, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Abrantes
authors.affiliation: Instituto Superior Técnico, Campus Tecnológico e Nuclear, Laboratório de Proteção e Segurança Radiológica, Estrada Nacional 10 (ao km 139,7), Bobadela LRS 2695-066, Portugal.
authors.forename: G
authors.initials: G
authors.lastname: Carvalhal
authors.affiliation: Instituto Superior Técnico, Campus Tecnológico e Nuclear, Laboratório de Proteção e Segurança Radiológica, Estrada Nacional 10 (ao km 139,7), Bobadela LRS 2695-066, Portugal.
authors.forename: M J
authors.initials: MJ
authors.lastname: Madruga
authors.affiliation: Instituto Superior Técnico, Campus Tecnológico e Nuclear, Laboratório de Proteção e Segurança Radiológica, Estrada Nacional 10 (ao km 139,7), Bobadela LRS 2695-066, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Reis
mesh_terms: D002845:Chromatography / Q000379:methods; D005507:Food Contamination, Radioactive / Q000032:analysis*; D006801:Humans; D011786:Quality Control; D012015:Reference Standards; D012588:Scintillation Counting / Q000379:methods* / Q000592:standards; D013326:Strontium Radioisotopes / Q000032:analysis* / Q000592:standards
chemical_list: D013326:Strontium Radioisotopes
keywords: Foodstuffs; Liquid scintillation; Quality control; Strontium-90