High‐energy collision‐induced dissociation tandem mass spectrometry of regioisomeric lactose palmitic acid monoesters using matrix‐assisted laser desorption/ionization
Bibliographic record
Abstract
RATIONALE: Structural characterization and differentiation of three newly synthesized lactose monopalmitate regioisomers at positions O-3, O-3' and O-6' were realized by single-stage matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) in the positive ion mode and by high-energy collision-induced dissociation tandem mass spectrometry (CID-MS/MS). METHODS: A MALDI-TOF/TOF analyzer was utilized for the analysis of these isobaric lactose monopalmitate regioisomers. The CID-MS/MS spectra were acquired using high-energy cid with a 2 kV potential difference between the source acceleration voltage and the collision cell. RESULTS: High-energy (CID) tandem mass spectrometry (MS/MS) analyses of the sodiated molecules, [M + Na](+), showed distinguishing cross-ring product ions and characteristic fingerprint product ions, which allowed the straight-forward mass spectrometric characterization of these different regiosiomers. CONCLUSIONS: This investigation allowed us to unravel the novel fragmentation behavior of the sodiated regioisoimer molecules obtained from the mono-substituted D-lactose fatty acid esters using high-energy CID-TOF/TOF-MS/MS analyses. The high-energy CID of the [M + Na](+) ions from the isobaric lactose monopalmitate regioiosmers promoted the formation of characteristic (0,2) A2 cross-ring cleavage product ions.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 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".