A cylindrical packing of the flexible polyurethane foam impregnated with a tertiary alkylamine: iodine complex is placed into the column made of a conventional plastic syringe. By passing a 5-dm3sample through the column in a single operation, the radioiodine is separated with 95% yield from water or higher than 80% yield from milk samples in less than 1 hr. The radioactivity of the compressed foam cylinder into 4 cm volume directly in the syringe can be measured in a well-type NaI(Tl) detector with about 45% counting efficiency. A lower limit of determination of about 0.04 Bq/dm3is achieved for 100 min of counting. The method can be used for routine determinations also under field conditions.