GC-MS Quantitation of Codeine, Morphine, 6-Acetylmorphine, Hydrocodone, Hydromorphone, Oxycodone, and Oxymorphone in Blood*
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
A method is described for the simultaneous analysis of seven opiates, codeine, morphine, 6-acetylmorphine, hydrocodone, hydromorphone, oxycodone, and oxymorphone, in blood samples by gas chromatography-mass spectrometry (GC-MS). One milliliter of blood is combined with an internal standard mixture containing 200 ng of each of the seven deuterated opiates. Two milliliters of acetonitrile is added to precipitate the proteins and cellular material. After centrifugation, the clear supernatant is removed, and the acetonitrile is evaporated. The remaining aqueous portion is adjusted to pH 9 with sodium bicarbonate buffer, and the drugs are extracted into chloroform/trifluoroethanol (10:1). The organic extractant is transferred and dried under nitrogen. The residue is reconstituted in dilute hydrochloric acid and washed consecutively with hexane and chloroform. The purified aqueous portion is adjusted to pH 9 with bicarbonate buffer, and the drugs are again extracted into chloroform/trifluoroethanol (10:1). The organic portion is removed from the aqueous fraction and dried under nitrogen. The residue is consecutively derivatized with methoxyamine and propionic anhydride using pyridine as a catalyst. The ketone groups on hydrocodone, hydromorphone, oxycodone, and oxymorphone are converted to methoximes. Hydroxyl groups present at the O3 and O6 positions of codeine, morphine, 6-acetylmorphine, hydromorphone, and oxymorphone are converted to their respective propionyl esters. After a postderivatization purification step, the extracts are analyzed by full scan GC-MS using electron impact ionization. The method is linear to at least 2000 ng/mL. Day-to-day precision (N = 15) at 500 ng/mL and 75 ng/mL were less than 10% for all seven targeted opiates. Extraction efficiencies at these two concentrations ranged from 50% to 68%. For each opiate, the limit of quantitation was 10 ng/mL, and the limit of detection was 2 ng/mL.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.003 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 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 it