title: Determination of radium-228 in foods and water.
abstract: A procedure was developed for the rapid determination of 228Ra by measuring its decay product 228Ac. The method is applicable to a variety of types of samples such as food and water. Food samples can be prepared by dry- or wet-ashing techniques. The 228Ac is precipitated with lanthanum carrier, dissolved, purified by solvent extraction, and finally decontaminated on anion and cation exchange resins. The 228Ac is counted in a thin-window, low-level gas flow beta counter. It may be necessary to count the sample several times to follow the 6 h half-life of 228Ac so that its purity is ensured. The method is sensitive to 1 pCi/sample of food ash and to 1 pCi/L of water.
mesh_terms: D005507:Food Contamination, Radioactive / Q000032:analysis*; D011883:Radium / Q000032:analysis*; D014873:Water Pollutants / Q000032:analysis*; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D014873:Water Pollutants; D014875:Water Pollutants, Radioactive; D011883:Radium