Standard Methods: 7500-U B: Uranium by Radiochemical Method
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Official Method Name
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7500-U B. Radiochemical Method |
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Current Revision
| Standard Methods Online |
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Media
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WATER |
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Instrumentation
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Alpha Scintillation |
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Method Subcategory
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Radiochemical |
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Method Source
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Citation
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Brief Method Summary
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The sample is acidified with hydrochloric or nitric acid and boiled to eliminate carbonate and bicarbonate ions. Uranium is coprecipitated with ferric hydroxide and subsequently separated. The ferric hydroxide is dissolved, passed through an anion-exchange column, and washed with acid, and the uranium is eluted with dilute hydrochloric acid. The acid eluate is evaporated to near dryness, the residual salt is converted to nitrate, and the alpha activity is counted. |
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Scope and Application
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Method 7500-U B, a radiochemical procedure, determines total uranium alpha activity without making an isotopic uranium analysis. |
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Applicable Concentration Range
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8-75 pCi/L |
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Interferences
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The only alpha-emitting radionuclide that may be carried through this procedure is protactinium-231. However, this isotope, which is a decay product of uranium-235, causes very little interference. Check reagents for uranium contamination by analyzing a complete reagent blank. |
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Quality Control Requirements
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See Section 7020 Quality Assurance/Quality Control. |
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Sample Handling
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Plastic or glass containers. Preserve sample by adjusting its pH to <2 with HCl or HNO3 at time of collection. |
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Maximum Holding Time
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1 year |
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Relative Cost
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$201 to $400 |
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Sample Preparation Methods
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