The IAEA-392 Algae material was prepared by the Analytical Quality Control Services of the International Atomic Energy Agency in co-operation with the Institute of Microbiology, Academy of Sciences of the Czech Republic in Trebon, during 1995. The IAEA-392 algae material (type: Scenedesmus obliquus 208) was produced under standard outdoor culture conditions. Mineral nutrients were prepared from p.a. chemicals and added as required to maintain the optimum balanced composition of the nutrient medium in the growing culture. After harvesting, the algae were stored in a coupled tank and continuously spray dried at moderate venting and temperature avoiding a damage of the cell structure. The bulk algae material and the sealed bottles were treated with gamma ray irradiation with a total dose of 25 kGy using a Co-60 source to improve long-term stability of the material by reducing microbial action.
| Analyte | Value | Unit | Expanded uncertainty U, k=2 | N | R/I/C |
| As | 0.175 | mg/kg | 0.017 | 4 | I |
| Ca | 2680 | mg/kg | 74 | 6 | R |
| Cd | 0.0173 | mg/kg | 0.0015 | 3 | I |
| Co | 3.33 | mg/kg | 0.13 | 7 | I |
| Cr | 4.57 | mg/kg | 0.19 | 7 | I |
| Cu | 23.2 | mg/kg | 1.8 | 6 | R |
| Fe | 497 | mg/kg | 16 | 8 | R |
| K | 8383 | mg/kg | 270 | 5 | I |
| Mg | 2376 | mg/kg | 92 | 4 | R |
| Mn | 67.5 | mg/kg | 1.7 | 5 | R |
| Na | 680 | mg/kg | 24 | 5 | R |
| Ni | 0.571 | mg/kg | 0.069 | 4 | R |
| Pb | 0.574 | mg/kg | 0.019 | 4 | R |
| Zn | 128.4 | mg/kg | 2.4 | 8 | R |
(N) Number of accepted laboratory means which are used to calculate the recommended or information values
(R/I) Classification of assigned property value (Recommended/Information)
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. Details concerning the criteria for qualification as a recommended or information value can be found in the respective report (attached). Expanded uncertainties were reviewed during stability monitoring in 2025, and a revised reference sheet was issued.
