Development, Optimization, and Validation of Radium-226 Measurement in Oyster, a Sentinel Organism by Mass Spectrometry
Bibliographic record
Abstract
Radium-226 (226Ra) measurement in living organisms, such as the American oyster (Crassostrea virginica), is an analytical challenge: the matrix complexity and the extremely low Ra levels require a purification/preconcentration step prior to its quantification. In this study, 5 g of dry oyster soft tissues and 1.6 g of shell were both mineralized, preconcentrated on an AG50W-X8 and a strontium-specific resin, and measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The volumes of digestate used in the method for both matrices were optimized to reach a high preconcentration factor without any risk of oversaturating the columns. Out of the 50 mL of digestates, 48 mL and 2.5 mL were determined as optimal volumes for soft tissues and shell, respectively. To obtain a higher preconcentration factor and a lower limit of quantification (LOQ) for shell samples, three aliquots of 2.5 mL digestate were run on three different sets of resins and, ultimately, combined for Ra analysis using ICP-MS. LOQs of 7.7 and 0.3 fg/g (260 and 11 µBq/g) were achieved for the oyster shell and soft tissues, respectively. The new protocols were applied on relevant samples: oyster soft tissues and shell from New Brunswick, Canada, and different types of reference materials, such as IAEA-470, oyster soft tissue and IAEA-A-12, and animal bones. 226Ra recovery of 105 ± 3% (n = 6) was achieved for IAEA-A-12 (animal bones), the closest available reference material to shell with a recommended value for 226Ra. Resin performances were investigated using 226Ra standard solution and real samples: each set of columns could be used more than 100 times without any significant reduction in Ra preconcentration efficiency. Although the method proposed and validated in this work was developed for oysters, it could easily be applied to other matrices by adjusting the volume of digestate run on the resins to avoid their oversaturation.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| 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 source (direct Gemma or distilled Codex), 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".