A large quantity of marine sediment was collected in 2002 from the Algerian coast of the Mediterranean Sea for use as an intercomparison material. It was deep-frozen, freeze dried, then ground and sieved. The particle size fraction <250 μm was homogenized and bottled in clean plastic bottles. After confirming general homogeneity via a pre-test (results not reported here), the samples were rebottled by packing aliquots of approximately 20 g into cleaned, brown borosilicate glass bottles with Teflon lined screw caps and sealed in plastic bags. Approximately 500 bottles were produced.
| Analyte | Value | Unit | 95% C.I. | N | R/I/C |
| Ag | 0.133 | mg/kg | 0.127 - 0.139 | 9 | R |
| Al | 78.2 | g/kg | 76.8 - 79.6 | 39 | R |
| As | 18.9 | mg/kg | 18.4 -19.4 | 57 | R |
| Ba | 268 | mg/kg | 241 - 295 | 8 | R |
| Br | 67 | mg/kg | 55 - 79 | 9 | R |
| Cd | 0.153 | mg/kg | 0.145 - 0.161 | 67 | R |
| Ce | 64.5 | mg/kg | 61.9 - 67.1 | 7 | I |
| Co | 12.9 | mg/kg | 12.6 - 13.2 | 65 | R |
| Cr | 136 | mg/kg | 134 - 138 | 79 | R |
| Cs | 6.40 | mg/kg | 6.03 - 6.77 | 8 | R |
| Cu | 30.8 | mg/kg | 30.2 - 31.4 | 89 | R |
| Eu | 1.18 | mg/kg | 1.11 - 1.25 | 6 | I |
| Fe | 40.8 | g/kg | 40.3 - 41.3 | 72 | R |
| Hf | 3.66 | mg/kg | 3.44 - 3.88 | 5 | I |
| Hg | 0.168 | mg/kg | 0.164 - 0.172 | 62 | R |
| K | 16.6 | g/kg | 13.7 - 19.6 | 7 | R |
| La | 33.7 | mg/kg | 31.4 - 36.0 | 8 | R |
| Li | 67.0 | mg/kg | 65.4 - 68.6 | 25 | R |
| Lu | 0.361 | mg/kg | 0.299 - 0.423 | 4 | I |
| MeHg | 0.17 | mg/kg | 0.12 - 0.23 | 9 | R |
| Mg | 11.5 | g/kg | 11.1 - 12.0 | 19 | R |
| Mn | 316 | mg/kg | 312 - 320 | 81 | R |
| Na | 13.5 | g/kg | 12.0 - 15.1 | 6 | I |
| Nd | 29.2 | mg/kg | 26.5 - 31.9 | 5 | I |
| Ni | 39.4 | mg/kg | 38.7 - 40.1 | 72 | R |
| Pb | 26.0 | mg/kg | 25.4 - 26.6 | 84 | R |
| Ru | 99.9 | mg/kg | 88.1 - 112 | 8 | R |
| Sb | 1.96 | mg/kg | 1.89 - 2.03 | 26 | R |
| Sc | 14.6 | mg/kg | 13.4 - 15.8 | 6 | I |
| Se | 0.78 | mg/kg | 0.70 - 0.85 | 23 | R |
| Sm | 5.61 | mg/kg | 5.26 - 5.96 | 6 | I |
| Sn | 2.32 | mg/kg | 2.17 - 2.47 | 23 | R |
| Sr | 302 | mg/kg | 296 - 308 | 41 | I |
| Ta | 1.03 | mg/kg | 0.94 - 1.12 | 6 | I |
| Tb | 0.696 | mg/kg | 0.582 - 0.810 | 5 | I |
| Th | 9.78 | mg/kg | 9.34 - 10.2 | 9 | R |
| U | 2.45 | mg/kg | 2.20 - 2.70 | 6 | R |
| V | 160 | mg/kg | 156 - 164 | 36 | R |
| Yb | 2.24 | mg/kg | 2.03 - 2.45 | 5 | I |
| Zn | 101 | mg/kg | 99 - 103 | 93 | R |
| Zr | 148 | mg/kg | 118 - 178 | 4 | I |
(N) Number of accepted laboratory means 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 an international interlaboratory comparison organized by the IAEA Marine Environment Laboratory, Monaco. The details concerning the criteria for qualification as a recommended or information value can be found in the report IAEA/AL/147 (attached).
