&EPA J technical FACT SHEET search BUILDING A SCIENTIFIC FOUNDATION FOR SOUND ENVIRONMENTAL DECISIONS Rapid Radiochemical Method Isotopic Uranium (^U, 235U, or234U) in Water Samples EPA's rapid radiochemical methods expedite analytical turnaround time for selected radionuclides while providing quantitative results that meet measurement quality objectives, Methods are applicable to samples where contamination is from either known or unknown origins. This fact sheet is intended for radioanalytical laboratory personnel, decision makers within the incident command structure, additional reoccupancy decision makers (e.g., state and local public health), and other field environmental response personnel. Method Summary: This method is based on the sequential elution of interfering radionuclides as well as other components of the matrix by extraction chromatography to isolate and purity uranium (238U, 235U, or 234U). Uranium is quantified by counting with alpha spectrometry. The method uses vacuum assisted flow to improve the speed of the separations. Prior to the use of the extraction resins, a water sample is filtered as necessary to remove any insoluble fractions, equilibrated with 232U tracer, and concentrated by either evaporation or calcium phosphate [Ca3(P04)2] precipitation. The sample test source is prepared by microprecipitation with neodym (III) fluoride. Standard laboratory protocol for the use of an alpha spectrometer should be used when the sample is ready for counting. Time to Process: 7 hr Includes radiochemical processing and counting Compare to traditional method (EPA 908,0): 9-14 hr Method Application The method is specific for soluble 238U, 235U, and 234U in drinking water and other aqueous samples. Application of this method should be validated by the laboratory using the protocols provided in Method Validation Guide for Qualifvina Methods Used bv Radiological Laboratories Participating in incident Response Activities, or the protocols published bv a recognized standards organization for method validation. Measurement Quality Objectives Required method uncertainty: 2.6 pCi/L Analytical action level (AAL): 20 pCi/L Required relative uncertainty: 13% above AAL Minimum detectable concentration: 1.5 pCi/L Sample quantity: ~ 200 mL Count time: At least 1 hr Equipment and Supplies Analytical balance: 10~4 g readability or better | Cartridge reservoirs: 10 or 20 mL syringe style with locking device, or equivalent | Centrifuge and 250 mL flasks | Filter apparatus with 25 mm diameter polysulfone filtration chimney, stem support, and stainless steel support or a single-use (disposable) filter funnel/filter combination | Filters: 0,45 pm membrane; 25 mm polypropylene with 0.1 pm pore size or equivalent | Laboratory supplies: 250 mL and 350 mL plastic/glass ware; 10 mL plastic culture tubes with caps; 100 pL pipettes and plastic tips; pH paper; stainless steel pianchets or other sample mounts able to hold the 25 mm filter; tweezers | Vacuum system: box; pump or laboratory system; white inner tips; yellow outer tips | Vortex mixer Sample Preservation Samples should be collected in 1 L plastic containers Analysis within 3 days of sampling: No preservation required Holding time >3 days: Adjust pH to <2 with concentrated nitric acid Waste Generated per Sample ~ 65 mL of acidic and 45 mL of slightly acidic waste ~ 1 mL hydrofluoric acid ~ 8 mL ethanol ~ 100-1000 mL pH neutral decanted solution if Ca3(PC4)2 coprecipitation performed 2 resin cartridges Contacts Proaram: Kathv Hall Technical: John Griaas 513-379-5260 334-270-3450 hali,kathy@epa.gov griggs.john@epa.gov Method Access: https://www.epa.aov/sites/production/files/2015- 06/documents/uranium in water rev 0 1 epa 402-M0- 001e.pdf U.S. Environmental Protection Agency EPA/600/S-17/062 Office of Research and Development, Homeland Security Research Program March 2017 ------- |