Coucke Line, Massarini Enrico, Ostijn Zachery, Beck Olof, Verstraete Alain G
Department of Laboratory Medicine, Ghent University Hospital, Ghent, Belgium.
Department of Public Health, Section of Legal Medicine, University of Rome "Tor Vergata", 00133 Rome, Italy; Department of Laboratory Medicine, Clinical Pharmacology Unit, Karolinska University Hospital, Stockholm, Sweden.
Clin Biochem. 2016 Sep;49(13-14):1072-7. doi: 10.1016/j.clinbiochem.2016.06.003. Epub 2016 Jun 8.
Δ(9)-Tetrahydrocannabinol (THC) can be measured in exhaled breath by using an aerosol particle collection device. The sampling procedure is simple, non-invasive and takes only 2-3min. In the present study we measured the amount of THC in exhaled breath of cannabis users at specific time intervals up to 3h after smoking one cannabis cigarette.
The breath concentration-effect relationship was studied by measuring the pulse rate and the pupil diameter to assess physiological changes. THC and the main metabolite 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol were analyzed in exhaled breath by a liquid chromatography-tandem mass spectrometry method. Thirteen subjects (9 males and 4 females, aged 23-24years) participated. Five of those were using cannabis more frequently than monthly.
THC was detected in most subjects already at baseline, concentrations increased following smoking and remained detectable for over 3h (mean THC concentration in breath at 3h: 1479pg/sample). Pulse rate (p=0.015) and pupil diameter (p=0.044) were significantly altered up to 30min after smoking. The detection window of cannabis in breath after smoking one cannabis cigarette in occasional and chronic smokers was at least 3h. Only THC was detected, and not the metabolite. The THC concentration in exhaled breath was related to the physiological changes that occur over time.
Exhaled breath can be used to detect recent cannabis exposure.
通过使用气溶胶颗粒收集装置，可以测量呼出气体中的Δ(9)-四氢大麻酚（THC）。采样过程简单、无创，仅需2 - 3分钟。在本研究中，我们在吸食一支大麻香烟后的特定时间间隔内，直至3小时，测量了大麻使用者呼出气体中的THC含量。
通过测量脉搏率和瞳孔直径来评估生理变化，研究呼吸浓度-效应关系。采用液相色谱-串联质谱法分析呼出气体中的THC及其主要代谢物11-去甲-9-羧基-Δ(9)-四氢大麻酚。13名受试者（9名男性和4名女性，年龄23 - 24岁）参与了研究。其中5人使用大麻的频率高于每月一次。
大多数受试者在基线时就已检测到THC，吸烟后浓度升高，并在3小时以上仍可检测到（3小时时呼出气体中THC的平均浓度：1479 pg/样本）。吸烟后30分钟内，脉搏率（p = 0.015）和瞳孔直径（p = 0.044）有显著变化。偶尔吸烟者和长期吸烟者在吸食一支大麻香烟后，呼出气体中大麻的检测窗口期至少为3小时。仅检测到THC，未检测到代谢物。呼出气体中THC的浓度与随时间发生的生理变化有关。
呼出气体可用于检测近期是否接触过大麻。
