A Ten-Day Glucuronide Stability Check Did Not Establish Unlimited Dried-Spot Stability
The dried-spot researchers found no observed cleavage of spiked THC-COOH glucuronide in their short stability check. That narrow result should retain its preparation and duration.
The experiment addressed a specific artifact
Reference material was added to blank blood at two concentrations, and the investigators examined the preparation directly after drying and after ten days of storage. The question was whether cleavage of the conjugate could contribute to measured unconjugated THC-COOH under those conditions.
A null cleavage finding has boundaries
The observation did not test every storage temperature, transport environment, collection card or duration. It also did not establish complete stability of parent THC, every metabolite or every biological component in an authentic specimen. Different stability questions require their own measurements.
Keep sample handling attached to the result
This check adds evidence about one potential source of analytical change. It does not guarantee that a specimen left under different conditions will retain the same concentrations indefinitely. A forensic interpretation should identify what was spiked, what transformation was sought and when it was assessed. The absence of observed cleavage is useful within that defined experiment, without becoming a universal claim that dried blood cannot change after collection.
Related analysis: the study’s broader findings and limitations.
