Is there fentanyl, or a fentanyl analog, in the vial?
A targeted mass-spectrometry method that looks for fentanyl and a list of analogs by their specific precursor-to-fragment transitions, at half a nanogram per millilitre. It is cheap because the identity run already has the sample on the instrument.
How it works
- 01Same sample, second methodAn aliquot of the identity-run solution is injected on a short, targeted method.
- 02Watch specific transitionsThe instrument monitors fentanyl's precursor ion (m/z 337.2) fragmenting to m/z 188.1 and 105.1, plus the transitions for each analog on the list.
- 03Compare with a spiked controlA control at the detection limit runs with every batch. If it doesn't show, the batch is invalid.
- 04ReportNot detected below 0.5 ng/mL in the reconstituted sample, or the value and the analog identified.
What the result means — and what it doesn't
Not detected means none of the listed compounds produced a signal above 0.5 ng/mL in the tested solution. The analog list is published and grows. A detection is reported with the compound name and value, and the vendor is notified before publication like any other result.
Why another lab might report a different number
- Analog coverage: a method that watches ten analogs will miss the eleventh. The list is on the result.
- Reconstitution volume changes the per-mL number, as with endotoxin.
- Immunoassay test strips have different cross-reactivity and a higher limit; they are a different tool.
That's why every result here prints the method and the limit next to the number. The full science article on why tests vary.
Methods described are Vialidate's own and are published so results can be compared with other laboratories' on equal terms. Nothing on this page is medical advice. ISO 17025 accreditation in progress.