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 | 0.016 | 4 | I |
| Ca | 2680 | mg/kg | 67.4 | 6 | R |
| Cd | 0.0173 | mg/kg | 0.0014 | 3 | I |
| Co | 3.33 | mg/kg | 0.122 | 7 | I |
| Cr | 4.57 | mg/kg | 0.180 | 7 | I |
| Cu | 23.2 | mg/kg | 1.74 | 6 | R |
| Fe | 497 | mg/kg | 13.6 | 8 | R |
| K | 8383 | mg/kg | 252.4 | 5 | I |
| Mg | 2376 | mg/kg | 78.8 | 4 | R |
| Mn | 67.5 | mg/kg | 1.54 | 5 | R |
| Na | 680 | mg/kg | 23.0 | 5 | R |
| Ni | 0.571 | mg/kg | 0.028 | 4 | R |
| Pb | 0.574 | mg/kg | 0.019 | 4 | R |
| Zn | 128 | mg/kg | 2.0 | 8 | R |
(N) Number of accepted
laboratory means which are used to calculate the recommended or information
values and their respective confidence intervals
(R/I/C) Classification assigned to the property
value for analyte (Recommended/Information/Certified)
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 can be found in the respective report
(attached).
