A sample of Tuna (Thunnus thynnus) was collected from the Mediterranean Sea in 2004. This sample was freeze-dried, ground, and sieved at 250 μm. The powder was homogenized and aliquots of about 30 g were packed into glass bottles to produce the IAEA-435 reference material. More details about the preparation of this reference material are provided in reference [INTERNATIONAL ATOMIC ENERGY AGERNCY, World-wide intercomparison exercise for the determination of organochlorine compounds and petroleum hydrocarbons in tuna homogenate IAEA-435, IAEA/AL/163, IAEA, Vienna (2006)). New homogeneity and characterization studies were performed on the IAEA-435 material to become IAEA-435A
Certified mass fraction values
PCB congeners
(Based on dry mass)
| Analyte | Unit | Certified value⁽ᵃ⁾ | Expanded uncertainty⁽ᵇ⁾ |
| PCB 28 | µg kg⁻¹ | 1.32 | 0.45 |
| PCB 31 | µg kg⁻¹ | 0.61 | 0.15 |
| PCB 52 | µg kg⁻¹ | 3.97 | 0.83 |
| PCB 101 | µg kg⁻¹ | 23.4 | 4.8 |
| PCB 105 | µg kg⁻¹ | 8.3 | 1.8 |
| PCB 118 | µg kg⁻¹ | 28.0 | 5.3 |
| PCB 138 | µg kg⁻¹ | 72 | 15 |
| PCB 149 | µg kg⁻¹ | 27.7 | 5.6 |
| PCB 153 | µg kg⁻¹ | 94 | 16 |
| PCB 156 | µg kg⁻¹ | 3.85 | 0.73 |
| PCB 170 | µg kg⁻¹ | 11.8 | 2.2 |
| PCB 180 | µg kg⁻¹ | 34.2 | 6.4 |
| PCB 187 | µg kg⁻¹ | 32.8 | 8.9 |
| PCB 194 | µg kg⁻¹ | 3.84 | 0.77 |
Certified mass fraction values
Chlorinated pesticides
(Based on dry mass)
| Analyte | Unit | Certified value⁽ᵃ⁾ | Expanded uncertainty⁽ᵇ⁾ |
| HCB | µg kg⁻¹ | 2.65 | 0.66 |
| pp’-DDD | µg kg⁻¹ | 13.6 | 3.4 |
| pp’-DDE | µg kg⁻¹ | 134 | 26 |
| pp’-DDT | µg kg⁻¹ | 18.3 | 4.0 |
| op'-DDE | µg kg⁻¹ | 2.10 | 0.56 |
| op'-DDD | µg kg⁻¹ | 2.67 | 0.69 |
| op'-DDT | µg kg⁻¹ | 7.2 | 1.8 |
| Dieldrin | µg kg⁻¹ | 5.5 | 1.6 |
| cis-Chlordane | µg kg⁻¹ | 7.1 | 2.1 |
| trans-Nonachlor | µg kg⁻¹ | 20.2 | 4.6 |
Certified mass fraction values
PBDE congeners
(Based on dry mass)
| Analyte | Unit | Certified value⁽ᵃ⁾ | Expanded uncertainty⁽ᵇ⁾ |
| BDE 28 | µg kg⁻¹ | 1.26 | 0.25 |
| BDE 47 | µg kg⁻¹ | 22.9 | 3.9 |
| BDE 66 | µg kg⁻¹ | 2.48 | 0.50 |
| BDE 99 | µg kg⁻¹ | 1.44 | 0.29 |
| BDE 100 | µg kg⁻¹ | 7.3 | 1.3 |
| BDE 153 | µg kg⁻¹ | 0.70 | 0.16 |
| BDE 154 | µg kg⁻¹ | 5.0 | 1.1 |
(a) Information on calculation of certified values
Certified values are calculated from the accepted data sets, each set being obtained by a different laboratory and/or a different method of determination following ISO Guide 35 [1].
(b) Information on uncertainty estimation
The uncertainty is expressed as an expanded uncertainty with a coverage factor k = 2 estimated in accordance with the JCGM 100:2008 [2] and ISO Guide 35 [1].
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 respective report (attached).
References
[1] INTERNATIONAL ORGANIZATION FOR STANDARDIZATION, Reference materials — Guidance for characterization and assessment of homogeneity and stability, ISO Guide 35:2017, ISO, Geneva (2017).
