The most prevalent of the five radium isotopes in ground water, having a half life greater than one day, are ²²⁶Ra and ²²⁸Ra. These two isotopes also present the greatest health risk compared to the other naturally occurring nuclides of equal concentrations if ingested via the water pathway.

Although primarily utilized on a water medium, this technique may be applicable for the measurement of the ²²⁶Ra content of any media once the medium has been completely decomposed and put into an aqueous solution.

The general methodology and basis of this technique are similar to the methodology “²²⁶Ra in Drinking Water (Radon Emanation Technique)” as described in the document EPA-600//4-80-032.

1.1 This test method covers the measurement of soluble, suspended, and total radium-226 in water in concentrations above 3.7 × 10⁻³ Bq/L. This test method is not applicable to the measurement of other radium isotopes.

1.2 This test method may be used for quantitative measurements by calibrating with a radium-226 standard, or for relative measurements by comparing the measurements made with each other.

1.3 This test method does not meet the current requirements of Practice D2777.

1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.

1.5 Hydrofluoric acid (HF) is very hazardous and should be used in a well-ventilated hood. Wear rubber gloves, safety glasses or goggles, and a laboratory coat. Avoid breathing any HF fumes. Clean up all spills promptly and wash thoroughly after using HF.

1.6 This standard does not purport to address all of the other safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.