Analysis of Stimulants in Oral Fluid and Urine by Gas Chromatography-Mass Spectrometry II: Pseudophedrine
Bibliographic record
Abstract
This study was designed to optimize a method for the identification and quantification of ephedrines in oral fluid (OF) and for its application to subjects taking different doses of pseudoephedrine. Ephedrines use by athletes is banned by World Anti-Doping Agency (WADA), only "in competition" if their concentration in urine exceeds the cutoff limit. The study aimed to establish if there is a correlation in terms of times of elimination and of concentration trends of ephedrine in OF and urine after administration of therapeutic doses of pseudoephedrine to various subjects. Results obtained from excretion studies performed on eight subjects showed reproducible times of disappearance of ephedrines from OF. Pseudoephedrine was generally at low concentrations or undetectable in oral fluid samples 12 h after administration, whereas urine samples collected in the same period of time showed higher ephedrine concentrations and exceeding cutoff values generally between 8 and 24 h after administration of the drug. Within- and between-individual variability was observed in terms of concentrations of pseudoephedrine in OF following the administration of the same dose. Only in the case of sustained-release drugs were constant pseudoephedrine concentrations achieved in OF.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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".