Document: NRC Regulatory Guide
Document ID: 535957c7-1203-410d-b709-8e4d381f00de
Document Type: regulatory_guide
Title: Measurements of Radionuclides in the Environment, Analysis of I-131 in Milk
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML1335/ML13350A246.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.3
CFR Part: 
CFR Title: 

Content:
second count. 'Murthy. G. K.. ei at "Method for Removing Iodine-131 from Milk," Journal or Dairy Science. 45:1066 (1962) 2Salki' M.. Omomo. Y.. "Determination of Iodine-131 in Milk, Quick Mcthod. for Radlochemical Analysi.," Technical Reportr. Series No. 95, JAFA, 1969. 3 'Bretthauer. F.. W.. Mullen. A. L.. Molghiss, A. A. "Milk • Trantfer Comparison.s of Dirfereni Chemckal Forn•s . or Radloiodine."' Health Physics, 22:257 (1972) A graphical resolution of 1.131 activity based on these three points mnay he performed. The sample should be held for at least a year to permit possible identitication of thie long.lived component should the need arise. Abstract of the Procedure Iodine-131 is removed from milk by concentrating the iodine on an anion exchange resin column and subsequently removing it from the resin by batch extraction using NaOCI. After reduction to 12 by hydroxylamine hydrochloride, the iodine is extracted into CC14 . reduced with bisulfite. and back extracted into water. The iodine is precipitated as palladous iodide. Chemical yield based on the added carrier iodine is determined gravimetrically. The 1.131 concentration is determined by counting the palladous iodide precipitate in a low-background beta counter. The yield for the procedure is 70 to 85'7r. Special Apparatus I. Ion exchange column, 2 cm dia. by about 10 cm long with standard taper fittings 2. Four-liter reservoir with standard taper fitting 3. Assorted sizes of glass beakers 4. Hot plate 5. Magnetic stirrer 6. Suction filtering apparatus 7. 250-ml and 125-ml separatory funnels 8. Clinical centrifuge 9. Low-baCkground beta counter (nominal background 41 count per min.) 10. Nylon rings and discs,,Mylar, glass fiber paper (2.8 cm) (see HASL 300) Reagents and Chemicals I. Iodide carrier, 10 mg/ml -dissolve 1.181 grams Nal in 100 ml water 2. Dowex I x 8. 20.50 mesh. Cl" form 3. 2M NaCI . dissolve 116.9 grams NaCI in I liter water 4. NaOCl, 5-6% (commercial strength) 5. HNO.t, concentrated 6.