Trace Condensate THC Was Not an Exact Quantified Concentration
The condensate study distinguished trace detection from quantification. One early post-use THC finding was a trace, so detection in every participant did not mean an exact THC concentration was reported for every sample.
Identification criteria could be met below the quantitative range
The researchers designated signals below quantification as trace when other criteria, including qualifier-to-quantifier ratio and retention time, were satisfied. Their approximate lower quantification limit in device units was 0.003 ng per device after the specified preparation. This was distinct from declaring no analyte present.
Preserve three different claims
Nondetection, trace detection and acceptable quantification are not interchangeable. A trace can support identification under the method’s criteria without supporting an exact number below its quantitative boundary. Likewise, absence of a quantified value is not automatically an absence-of-exposure finding.
Do not turn a trace into an impairment value
The study involved twelve participants who inhaled cannabis and two non-users, with limited post-use sampling. It did not validate an individual impairment cutoff. When comparing a trace with another device or specimen, retain collection method, preparation, units and sensitivity. The reported signal cannot be converted directly into a blood concentration, consumed dose or precise time of use.
Related analysis: the condensate proof-of-concept study.
Research cited
Berry and colleagues (2024). Cannabinoids detected in exhaled breath condensate after cannabis use. DOI: 10.1088/1752-7163/ad6347.
