Report of the Fourth Interlaboratory Comparison Organised by the Community Reference Laboratory for Heavy Metals in Feed and Food- Total Cd, Pb, As, Hg and Methylmercury in Seafood
Bibliographic record
Abstract
The Institute for Reference Materials and Measurements (IRMM) of the Joint Research Centre (JRC), a Directorate-General of the European Commission, operates the Community Reference Laboratory for Heavy Metals in Feed and Food (CRL-HM). One of its core tasks is to organise interlaboratory comparisons (ILCs) among appointed National Reference laboratories (NRLs). This report presents the results of the fourth ILC of the CRL-HM which focused on the determination of total Cd, Pb, As, Hg and methylmercury (related to dry mass) in seafood. \n\nThe test material used in this exercise was the Certified Reference Material (CRM) TORT-2, lobster hepatopancreas, of the National Research Council of Canada. The material was rebottled and relabelled to prevent recognition by the participants and it was dispatched in the first half of May 2008. Each participant received one bottle containing approximately 20g of test material. Thirty-four participants from twenty-six counttries registered to the exercise of which thirty-three sets of results were reported for Cd and total mercury, thirty-two for Pb, twenty-seven for arsenic and four for methylmercury. One laboratory reported two stes of values for Cd, Pb, Hg and As obtained with two different techniques, respectively. The Assigned values were the certified values taken from the TORT-2 certificate.\n\nThe uncertainties of the respective assigned values, uref, were taken directly from the CRM certificate as provided by the producer. Participants were invited to report the uncertainty on their measurements. This was done by all the laboratories taking part in the exercise.\n\nLaboratory results were rated with z and zeta scores in accordance with ISO 13528. Standard deviation for profficiency assessment (also called target standard deviation) were calculated, using the modified Horwitz equation, and were 9.76% for total Cd, 18.74% for total Pb, 10% for total As, 19.48% for total Hg and 21.24% for methylmercury.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".