Validation of an EMIT® Screening Method to Detect 6-Acetylmorphine in Oral Fluid
Bibliographic record
Abstract
An automated assay was modified and validated to qualitatively screen for 6-acetylmorphine (6-AM) in oral fluid using the Siemens EMIT II(®) Plus 6-AM urine assay. The validation utilized an oral fluid calibrator at the currently proposed Substance Abuse and Mental Health Services Administration cutoff concentration of 4 ng/mL, as well as quality control material prepared and validated through liquid chromatography-tandem mass spectrometry. All calibrator, quality control and unknown specimens were analyzed based on the dilution and buffering system of the Quantisal(®) oral fluid collection device. Immunoassay parameters such as the pipetted sample and reagent volumes as well as photometric read times were adjusted as part of the assay modification process. Validation experiments included the determination of intra- and inter-day precision and reproducibility, limits of detection (LODs), assay selectivity, stability studies and a specimen agreement study (n = 132). The 6-AM assay performed well in all validation experiments, over multiple days and under various laboratory conditions. The LOD was determined to be 1.844 ng/mL. The assay sensitivity, specificity and overall misclassification rate were found to be 90, 100 and 6%, respectively.
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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 | 0.005 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".