Characterization of Naphthenic Acids from Athabasca Oil Sands Using Electrospray Ionization: The Significant Influence of Solvents
Bibliographic record
Abstract
There is a need to develop routine and rugged methods for the characterization of oil sands naphthenic acids present in natural waters and contaminated soils. Mass spectra of naphthenic acids, obtained using a variant of electrospray ionization coupled with a Fourier transform ion cyclotron resonance mass spectrometer, are shown here to vary greatly, reflecting their dependence on solubilities of the acids in organic solvents. The solubilities of components in, for example, 1-octanol (similar solvent to fatty tissue) compared to polar solvents such as methanol or acetonitrile are used here as a surrogate to indicate the more bioavailable or toxic components of naphthenic acids in natural waters. Monocarboxylic compounds (CnH2n+zO2) in the z=-4, -6, and -12 (2-, 3-, and 6-ring naphthenic acids, respectively) family in the carbon number range of 13-19 were prevalent in all solvent systems. The surrogate method is intended to serve as a guide in the isolation of principle toxic components, which in turn supports efforts to remediate oil sands contaminated soils and groundwater.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| 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) | 0.001 | 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".