A dual-detection chromatography paper used smartphone imaging for higher drug loads and a more sensitive densitometric method for spiked plasma.
The laboratory study separated diazepam, oxazepam, and the degradation product ACB on high-performance thin-layer chromatography plates. One detection approach used a color reagent, smartphone photographs, and image analysis. The other used ultraviolet densitometry at 230 nm.
Smartphone calibration covered 3–35 micrograms per spot for diazepam and ACB and 5–35 micrograms per spot for oxazepam. Densitometry covered 0.2–1 microgram per spot. These quantities describe material applied to the plate; they are not blood concentration thresholds.
The smartphone approach was applied to pharmaceutical formulations. The more sensitive densitometric approach was used for diazepam and oxazepam in spiked human plasma, with ACB serving as internal standard. Spiked material supports an analytical feasibility assessment, but it does not reproduce every challenge in authentic patient or postmortem specimens.
A forensic summary should identify which detector produced each result, the extraction process, calibration range, and matrix studied. The paper does not establish that a phone camera can directly identify therapeutic blood concentrations or replace a laboratory’s validated biological testing method. Its contribution is a comparison of accessible detection strategies within a defined chromatographic platform.
Original analysis of the supplied journal article, identified as PMC12931046.