Baratta E J, Lumsden E M
J Assoc Off Anal Chem. 1982 Nov;65(6):1424-8.
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.
开发了一种通过测量其衰变产物228Ac来快速测定228Ra的方法。该方法适用于多种类型的样品，如食品和水。食品样品可以通过干灰化或湿灰化技术制备。228Ac用镧载体沉淀，溶解，通过溶剂萃取纯化，最后在阴离子和阳离子交换树脂上进行去污。228Ac在薄窗、低水平气流β计数器中计数。可能需要对样品进行多次计数以跟踪228Ac的6小时半衰期，从而确保其纯度。该方法对食品灰分中1 pCi/样品和水中1 pCi/L敏感。
