Gamma-ray spectroscopic determination of iodine-131 and cesium-137 in foods: two collaborative studies.
The AOAC method for iodine-131, cesium-137, and barium-140 in milk by gamma-ray spectroscopy (48.025-48.029) was extended to include other foods for the radionuclides iodine-131 and cesium-137. Two collaborative studies were performed to validate this extension. In the first study, a food sample containing 119 pCi 131I/kg and 53 pCi 137Cs/kg was sent to each of 45 laboratories for triplicate analyses. For 25 responses, the mean of the reported values was 123.8 pCi/kg for iodine-131, and for 27 responses, the mean was 53.4 pCi/kg for cesium-137. Repeatability (within-laboratory) standard deviations (Sr) for iodine-131 and cesium-137 were 4.6 and 3.7 pCi/kg, respectively. Reproducibility (among-laboratories) standard deviations (SR) for iodine-131 and cesium-137 were 12.1 and 6.0 pCi/kg, respectively. In the second study, a food sample containing 25 pCi 131I/kg and 27 pCi 137Cs/kg was sent to each of 54 laboratories for triplicate analyses. For 21 responses, the mean of the reported values was 25.0 pCi/kg for iodine-131, and for 19 responses, the mean was 28.9 pCi/kg for cesium-137. Sr Values were 4.0 and 1.6 pCi/kg for iodine-131 and cesium-137, respectively, and SR values were 5.0 and 2.8 pCi/kg, respectively. The method extension was adopted official first action.
Baratta
E J
EJ
Food and Drug Administration, Winchester Engineering and Analytical Center, Winchester, MA 01890.
Easterly
D G
DG
D000818:Animals; D002417:Cattle; D002588:Cesium Radioisotopes / Q000032:analysis*; D005504:Food Analysis; D005506:Food Contamination; D007457:Iodine Radioisotopes / Q000032:analysis*; D008892:Milk / Q000032:analysis; D013051:Spectrometry, Gamma
D002588:Cesium Radioisotopes; D007457:Iodine Radioisotopes