Quantification of elution and breakthrough of molybdate solutions through varying DowexTM-1 resin amounts for translation to Mo99/Tc99m separations
Bibliographic record
Abstract
1008 Objectives To determine effect of molybdenum concentrations and DowexTM-1 resin amounts on recovery, retention onto the resin and breakthrough into tetrabutylammonium bromide solvent (TBAB) solvent. Methods MoO3 solutions of molybdenum concentration of 100 and 250mg/mL in 5M NaOH were passed through three separate fresh DowexTM-1 columns containing five different DowexTM-1 amounts (45, 75, 125, 175, and 250mg) in consecutive serial runs. The eluent was collected in a pre-weighed vial. The column was washed with saline and eluted with 5mL TBAB in dichloromethane (1mg/5mL). A 50µL sample of the collected solution, the saline wash and TBAB solution eluents were retained for ICP-OES analysis. Results Average % recoveries through 45, 75, 125, 175, and 250mg amounts of DowexTM-1 resin at 100mg/mL Mo in 5M NaOH were, respectively, 99.2, 99.2, 96.5, 97.5 and 97.3 and at 250mg/mL were 97.8, and 97.5, 97.6, 96.5 and 97.3 (n=3). From the component retained on DowexTM-1 column, subsequent Mo elutions into TBAB solvent were low, with average ppm values of 0.332 (1.81x10-4% of the original Mo), 0.444 (2.47x10-4%), 1.569 (9.00x10-4%), 2.511 (1.43x10-3%) and 3.730 (1.13x10-2%) for the 100mg/mL solution and 1.827 (4.41x10-4%), 0.961 (2.35x10-4%), 2.709 (6.60x10-4%), 2.924 (7.05x10-4%), and 11.274 (2.73x10-3%) for the 250mg/mL solution using 45, 75, 125, 175, and 250mg DowexTM-1 amounts, respectively (n=3). Increasing amounts of DowexTM-1 for the 100mg/mL solution led to a slightly lower recovery of molybdenum through the column (a trend not seen with the 250mg/mL solution), and a noticeable increase in the amount eluted into TBAB solvent. The predominant locations of retained Mo (total of Conclusions DowexTM-1 is an effective and robust extraction procedure that provides very low molybdenum breakthrough amounts into TBAB solvent. However, for efficient separation parameters a range-relationship is observed between concentration molybdenum and amount of resin on the column. Research Support Partly supported by Natural Resources Canada’s Non-Reactor Isotope Supply Program
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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".