An Automated Cannabinoid Assay Still Began With Manual Preparation
The automated platform handled solid-phase extraction and subsequent analytical steps, but blood and urine first underwent specified pretreatment. Calling the assay automated does not make those earlier steps irrelevant.
Where automation began
The procedure used 0.25 mL of specimen with added internal standards. Whole blood underwent protein precipitation, while urine also required enzymatic deglucuronidation before precipitation. Samples were centrifuged, and the supernatant was transferred into a vial placed on the automated sampler. The system then performed the programmed extraction workflow.
Upstream steps determine what enters the machine
Timing, reagent proportions, hydrolysis and transfer affect the material presented to automated extraction. A reproducible robot sequence cannot retrospectively establish that all upstream preparation matched the validated procedure. Nor does automation by itself identify which person performed or documented a manual step.
What the description supports
The method aimed to reduce labor and improve throughput and reproducibility. Those benefits should be distinguished from an entirely unattended specimen-to-result process. In a laboratory review, identify the boundary between manual and automated work and examine records for both. The study validated a particular analytical workflow in human biological matrices; it did not establish that automation makes concentrations a direct test of behavior or eliminates all measurement uncertainty.
Related analysis: the automated cannabinoid assay.
Research cited
Frei and colleagues (2022). Quantitative determination of five cannabinoids in blood and urine by gas chromatography tandem mass spectrometry applying automated on-line solid phase extraction. DOI: 10.1002/dta.3241.
