Radium-228 and combined radium measurement context
EPA Method 904.0 for radium-228: radium is separated from the sample by co-precipitation with barium sulfate, and the actinium-228 that forms from radium-228 is separated and its beta activity counted. Combined radium-226 and radium-228 is also offered: radium-226 is measured by EPA Method 903.1, radon emanation. Radium is co-precipitated with barium sulfate, the precipitate is dissolved and sealed in a bubbler while radon-222 grows in from the radium-226, and the radon is then transferred to a scintillation cell and counted for alpha activity. The radium-226 and radium-228 results are added to give combined radium. Reported in pCi/L.
Define the specialty measurement
State the isotope, fiber or chemical-form question as applicable. A total, gross or combined measurement does not automatically answer a species-specific question.
Include the complete project requirement
Provide the matrix, target analytes, required method, fraction, units and reporting limits. Include the permit or monitoring instructions where results will support a regulatory submission. Naming this method does not establish blanket compliance eligibility.
Resolve collection before sampling
Use the bottle, preservation and delivery instructions assigned to the agreed scope. Identify each location and collection time, and document any deviation. The final analytical plan must fit the submitted material and its intended use.
Related testing & guidance
Technical & service references
Vanguard service detailsSource review: November 8, 2026. The agreed method and project scope govern the testing.