รายละเอียดเอกสาร

The test portion is treated with NaHSO3 to convert all the iodine to a common (I−) oxidation state. Iodide is isolated and concentrated on an ion-exchange column. The iodide is oxidized on-column to iodate by NaOCl solution and eluted by this solution. The NaOCl is decomposed and the iodate is reduced by hydroxylamine hydrochloride solution to elemental iodine which is extracted by CC14. The iodine is again reduced to iodide and re-extracted into aqueous solution by NaHSO3 solution. The iodide is coprecipitated with palladium iodide (PdI2) and the recovery of the carrier is determined gravimetrically. The iodine-131 in the carrier is counted by a beta-gamma coincidence or by a low-background beta counter.