Simultaneous measurement of cortisol and cortisone in saliva by LC-MS/MS: Application in basal and stimulated conditions
Bibliographic record
Abstract
Salivary cortisol is an increasingly popular tool in endocrine, psychological and sports studies. Immunoassays used for its measurement are limited by cross-reactivity from related steroids, mainly cortisone, which is abundant in saliva. A method was developed for the simultaneous measurement of cortisol and cortisone (SalF and SalE respectively) in saliva using LC-MS/MS. 40 μl of extract was injected onto a C8 4×2 mm guard cartridge attached to a C18 3.5 μm 2.1×50 mm analytical column. The eluant was then injected into a tandem mass spectrometer. The method was linear up to 100 nmol/l for SalF and 200 nmol/l for SalE and the lower limits of quantitation were 0.5 nmol/l (SalF) and 2.5 nmol/l (SalE). No evidence of ion suppression was found and precision, accuracy and recovery were within internationally accepted limits for both compounds. Samples were stable at room temperature for at least 2 weeks. The method was applied in 24 healthy volunteer morning and bed-time saliva samples and 96 saliva samples from 32 normal SSTs (peak serum cortisol >500 nmol/l). Results are reported in the table below as median (range). SalF, SalE and the SalF/SalE ratio were significantly greater in the morning (am versuss pm, P
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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 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".