Abstract: A system for collecting cannabis and the psychoactive component tetrahydrocannabinol from a sample of exhaled breath is disclosed. Single or multiple exhaled breaths are conditioned by removing contaminants, and regulating flow rate and/or pressure to collect a sample of tetrahydrocannabinol for timely local or remote analysis. The cannabis detection system comprises a containment trap for removing interfering materials from the breath of the subject and a collection component for sampling components of breath introduced into the system through the containment trap for analysis to determine a presence of THC in the breath.