Applied Chemical and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, United States of America.
Colorado School of Public Health, University of Colorado Anschutz Medical, 13001 E. 17th Place, Aurora, CO, United States of America.
J Breath Res. 2024 Jul 23;18(4):041002. doi: 10.1088/1752-7163/ad6347.
Cannabinoids can be detected in breath after cannabis use, but different breath matrices need to be explored as studies to date with filter-based devices that collect breath aerosols have not demonstrated that breath-based measurements can reliably identify recent cannabis use. Exhaled breath condensate (EBC) is an unexplored aqueous breath matrix that contains condensed volatile compounds and water vapor in addition to aerosols. EBC was collected from participants both before and at two time points (0.7 ± 0.2 h and 1.7 ± 0.3 h) after observed cannabis use. Eleven different cannabinoids were monitored with liquid chromatography tandem mass spectrometry. Five different cannabinoids, including Δ-tetrahydrocannabinol (THC), were detected in EBC collected from cannabis users. THC was detected in some EBC samples before cannabis use, despite the requested abstinence period. THC was detected in all EBC samples collected at 0.7 h post use and decreased for all participants at 1.7 h. Non-THC cannabinoids were only detected after cannabis use. THC concentrations in EBC samples collected at 0.7 h showed no trend with sample metrics like mass or number of breaths. EBC sampling devices deserve further investigation with respect to modes of cannabis use (e.g, edibles), post use time points, and optimization of cannabinoid recovery.
大麻使用后可在呼出气中检测到大麻素，但需要探索不同的呼出气基质，因为迄今为止使用基于过滤器的设备收集呼出气气溶胶的研究表明，基于呼出气的测量不能可靠地识别最近的大麻使用情况。呼出气冷凝物（EBC）是一种未被探索的水性呼出气基质，除气溶胶外，还含有浓缩的挥发性化合物和水蒸气。在观察到大麻使用后，从参与者中收集了 EBC，分别在使用前和两个时间点（0.7±0.2 h 和 1.7±0.3 h）进行收集。使用液相色谱串联质谱法监测了 11 种不同的大麻素。在来自大麻使用者的 EBC 中检测到五种不同的大麻素，包括Δ-四氢大麻酚（THC）。尽管请求了禁欲期，但在使用大麻之前，在一些 EBC 样本中检测到了 THC。在使用后 0.7 h 收集的所有 EBC 样本中都检测到了 THC，并且所有参与者在 1.7 h 时都减少了 THC。非 THC 大麻素仅在使用大麻后被检测到。在 0.7 h 收集的 EBC 样本中，THC 浓度与质量或呼吸次数等样本指标没有趋势。EBC 采样设备需要进一步研究，包括使用方式（例如，食用品）、使用后时间点以及大麻素回收的优化。
