The material was obtained from the “Vladimirovka” collective farm, Polesskoe, Kiev, Ukraine, in summer 1990. The material was air dried and milled to less than 0.3 mm by the Brjansk Centre for Agricultural Radiology and Chemistry. Then 75 kg of the bulk material were recombined and homogenized at an IAEA collaborating centre (the Hungarian National Institute for Food Inspection) by mixing the powder in a 300 L drum for 72 hours, and then dispensed into plastic bottles, sealed with polyethylene caps in 100 g units, and labelled with the code IAEA-372. Subsequently, the samples were irradiated to a dose of 25.5 kGy minimum using a Co-60 source according to EN ISO 13485:2003 to ensure long-term stability of the material by inhibiting microbial action.
Reference date for decay correction: 2006-06-01
| Analyte | Value | Unit | Uncertainty |
| 40K | 1060 | Bq/kg | 56 |
| 137Cs | 11320 | Bq/kg | 360 |
The values listed above were established on the basis of statistically valid results submitted by laboratories which had participated in one or more international interlaboratory comparisons organized by the Chemistry Unit, IAEA Laboratories, Seibersdorf. The details concerning the criteria for qualification as a recommended or information value may be found in the respective report.
References:
SHAKHASHIRO, A., SANSONE, U., ARNOLD, D., DRYAK, P., LA ROSA, J.J., JEROME, S.M., MAKAREWICZ, M., MENTCHEVA, J., SATO, K., TARJAN, S., The new IAEA-372 grass-certified reference material for 40K and 137Cs, Appl. Rad. Isotop. 66 (2008) 1718-1721.
