TY  - JOUR
PY  - 2013//
TI  - Cannabinoids in exhaled breath following controlled administration of smoked cannabis
JO  - Clinical chemistry
A1  - Himes, S.K.
A1  - Scheidweiler, K.B.
A1  - Beck, O.
A1  - Gorelick, D.A.
A1  - Desrosiers, N.A.
A1  - Huestis, M.A.
SP  - 1780
EP  - 1789
VL  - 59
IS  - 12
N2  - BACKGROUND: Δ9-Tetrahydrocannabinol (THC), 11-nor- 9-carboxy-THC (THCCOOH), and cannabinol (CBN) were measured in breath following controlled cannabis smoking to characterize the time course and windows of detection of breath cannabinoids. <br><br>METHODS: Exhaled breath was collected from chronic (≥4 times per week) and occasional (<twice per week) smokers before and after smoking a 6.8% THC cigarette. Sample analysis included methanol extraction from breath pads, solid-phase extraction, and liquid chromatography- tandem mass spectrometry quantification. <br><br>RESULTS: THCwas the major cannabinoid in breath; no sample contained THCCOOH and only 1 contained CBN. Among chronic smokers (n=13), all breath samples were positive for THC at 0.89 h, 76.9% at 1.38 h, and 53.8% at 2.38 h, and only 1 sample was positive at 4.2 h after smoking. Among occasional smokers (n = 11), 90.9% of breath samples were THC-positive at 0.95 h and 63.6% at 1.49 h.Oneoccasional smoker had no detectable THC. Analyte recovery from breath pads by methanolic extraction was 84.2%-97.4%. Limits of quantification were 50 pg/pad for THC and CBN and 100 pg/pad for THCCOOH. Solid-phase extraction efficiency was 46.6%-52.1% (THC) and 76.3%-83.8% (THCCOOH, CBN). Matrix effects were -34.6% to 12.3%. Cannabinoids fortified onto breath pads were stable (≤18.2% concentration change) for 8 h at room temperature and -20°C storage for 6 months. <br><br>CONCLUSIONS: Breath may offer an alternative matrix for identifying recent driving under the influence of cannabis, but currently sensitivity is limited to a short detection window (0.5-2 h). © 2013 American Association for Clinical Chemistry.   Keywords: Cannabis impaired driving<p /> <p>Language: en</p>
LA  - en
SN  - 0009-9147
UR  - http://dx.doi.org/10.1373/clinchem.2013.207407
ID  - ref1
ER  -