Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry and Derivatization for the Identification of Polar Carbonyl Disinfection By-Products
Bibliographic record
Abstract
Derivatization with 2,4-dinitrophenylhydrazine (DNPH) in combination with LC-ESI/MS/MS was successfully applied to investigate polar disinfection by-products with carbonyl groups. The collision-induced dissociation mass spectra (CID-MS) show distinct fragments of the DNPH moiety which facilitates selective measurements of different carbonyl groups by tandem mass spectrometric experiments like precursor ion scans (e.g. m/z 163 for aldehydes; m/z 152 for ketones, m/z 152 for dicarbonyls and hydroxycarbonyls). Several multifunctional carbonyls could be tentatively identified in treated water samples by putting together all information of HPLC separation, derivatization, precursor ion scans, and CID-MS. However, DNPH derivatization is not a suitable reagent for halogenated carbonyl compounds due to side reactions. The chlorine is substituted by DNPH. O-(carboxymethyl) hydroxylamine (CMHA) is a suitable alternative. CMHA derivatization is specifically aimed at the carbonyl group and does not affect the chlorine. The formed oxime derivatives reveal abundant signal intensity in ESI and meaningful CID-MS with common fragments of the CMHA moiety and diagnostic fragments of the carbonyl moiety.
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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) | 0.000 | 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 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".