Limits of detection of polydimethylsiloxane in29Si NMR spectroscopy
Bibliographic record
Abstract
Limits of detection for neat poly(dimethylsiloxane) (PDMS), as detected via (29)Si NMR spectroscopy, were determined by the IUPAC, graphical, and propagation of errors methods from calibration curves obtained using a 7.05 Tesla superconducting magnet equipped with a magic angle spinning (MAS) NMR probe. Under conditions permitting full relaxation of the nuclear spins (recycle time >150 sec), the limit of detection with 128 transients was 1.7, 2.2, and 3.7 mg PDMS (23, 30, and 50 micromoles elemental Si) for the IUPAC, graphical, and propagation of errors methods, respectively. A higher limit of detection results when additional sources of uncertainty are considered. From the strict dependence of the limit of detection on the inverse of the square root of the number of transients signal-averaged, it is possible to extrapolate to a limit of detection of 183 microg PDMS (2.47 micromoles elemental Si) for a 24-hr signal averaging period. This limit of detection is 3 orders of magnitude higher than silicon levels found in human blood.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".