Stored Blood Did Not Show a Simple THC-to-CBN Conversion Pattern
A decrease in stored THC should not automatically be explained as conversion into measurable CBN. The authentic blood study did not show a simple reciprocal pattern in which every THC loss produced a CBN increase.
The analytes had separate storage findings
High blood THC pools decreased after one week at room temperature, while high-pool CBN did not significantly change over that interval. CBN also showed no significant change over twenty-six refrigerated weeks. The longer frozen-storage analysis found an overall CBN decline, although individual time-point comparisons with baseline were not significant.
A plausible chemical pathway is not a mass balance
The study measured concentrations under defined storage conditions. It did not establish that CBN accounted for all lost THC or identify every loss mechanism. Adsorption, degradation and matrix effects are questions to evaluate rather than causes to assign from the direction of one result. The relevant analytes also had different starting concentrations and quantifiable sample counts.
Avoid an unsupported correction
A reviewer cannot reconstruct original THC simply by adding later CBN to remaining THC or assuming a fixed conversion percentage from this study. The authentic specimen, container, storage and analytical details must remain attached. These findings address postcollection chemistry, not a new exposure event or a direct measurement of the person’s condition before collection.
Related analysis: free metabolite changes during specimen storage.
Research cited
Scheidweiler and colleagues (2013). In Vitro Stability of Free and Glucuronidated Cannabinoids in Blood and Plasma Following Controlled Smoked Cannabis. DOI: 10.1373/clinchem.2012.201467.
