Analysis of tretoquinol and its metabolites in human urine by liquid chromatography–tandem mass spectrometry
Bibliographic record
Abstract
Tretoquinol (trimetoquinol), a β2-agonist, has been explicitly listed on the World Anti-Doping Agency Prohibited List 2019 since January 2019; however, it has been distributed as an antiasthmatic on the medical market. This study aimed to develop a liquid chromatography-tandem mass spectrometric method for the quantification of tretoquinol (free form plus glucuronide) in human urine for doping control purposes. An excretion study (n = 6) of tretoquinol hydrochloride hydrate (6 mg) was performed, and urine samples were collected prior to oral administration and during the first 48 h, along with spot urine samples at 7 and 14 days after administration. All the urine samples were analysed using the developed method. The limit of detection for the developed method was 0.03 ng/mL. The inter-day precision for the target analyte was excellent (2.7% to 9.2%), and the inter-day accuracy of target analyte was -0.6% to -3.6%. In all subjects, tretoquinol (free form plus glucuronide conjugate) was identified up to 48 h after administration. The maximum concentrations were in the range of 12.4-78.8 ng/mL and the mean concentration was 55.3 ng/mL. The metabolites O-methylated tretoquinol, tretoquinol sulphate and O-methylated tretoquinol sulphate could be also identified in human urine after administration. The longest-lasting urinary metabolite of tretoquinol currently known, O-methylated tretoquinol, is also likely to be a useful marker in doping controls.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.006 |
| 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".