[en] As a result of the implementation of the as low as reasonably achievable philosophy to the nuclear power industry, recent US Nuclear Regulatory Commission requirements have prompted high-sensitivity radiochemical analysis for the measurement of iodine-131 in milk. The commonly employed technique incorporates costly palladium iodide as the final precipitate in the radiochemical purification of the iodine chemical species. The procedure presented here outlines the advantages of using cuprous iodide as the final precipitate. These include lower cost per analysis, consistent recoveries, better precipitate matrix, and good self-absorption characteristics. Typical lower-limit-of-detection values and operating characteristics obtained for high-sensitivity beta-gamma analysis are presented as well as gas proportional counting and a comparison of radiochemical and germanium (lithium) spectrometric results for environmental samples collected during the recent Chinese weapons fallout incident