EPA-ORD / EPA-OST: 908.0: Uranium in Drinking Water
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Official Method Name
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Uranium in Drinking Water - Radiochemical Method 908.0 |
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Current Revision
| Version 2.0, June 1999. |
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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 radium in the drinking water sample is collected by co-precipitation with barium and lead sulfate, and purified by re-precipitation from EDTA solution. Citric acid is added to the drinking water sample to assure that complete interchange occurs before the first precipitation step. The final BaSO4 precipitate, which includes radium-226, radium-224, and radium-223 is alpha counted to determine the total disintegration rate of the radium isotopes. |
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Scope and Application
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This method covers the measurement of the total soluble alpha emitting radioisotopes of radium, namely radium-223, radium-224 and radium-226 in drinking water. Part 141 of the Interim Primary Drinking Water Regulations, Federal Register, July 9, 1976, has promulgated the maximum contaminant levels of radium-226 plus radium-228 not to exceed 5 pCi/L. |
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Applicable Concentration Range
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None specified. |
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Interferences
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The only alpha-emitting radionuclide that may come through the chemistry and cause interference would be protactinium-231. However, protactinium-231 results from the decay of uranium-235, a low abundance natural isotope of uranium, and would therefore cause only a very small interference. |
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Quality Control Requirements
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The counting efficiency for radium alpha particles with barium sulfate carrier present must be determined using a standard (known) radium alpha activity and 32mg of barium carrier as BaSO4. |
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Sample Handling
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Sample preservation (1N HNO3) to a pH of 2. |
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Maximum Holding Time
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See Section 3 - Method 900 |
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Relative Cost
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Unknown |
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Sample Preparation Methods
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None provided. |
