Determination of cannabinoid vapor pressures to aid in vapor phase detection of intoxication
Determination of cannabinoid vapor pressures to aid in vapor phase detection of intoxication
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DOI：
10.1016/j.forc.2017.06.003
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发表时间：
2017-09-01
影响因子：
2.7
通讯作者：
Bruno, Thomas J.
中科院分区：
文献类型：
--
作者：
Lovestead, Tara M.;Bruno, Thomas J.
目前正在寻找一种可靠的方法，用呼气测醉器来检测大麻中毒。为了设计这样的装置，了解所研究化合物的基本热力学是很重要的。给出了两种重要的大麻素，大麻二酚（CBD）和δ(9)-四氢大麻酚（δ (9)-THC）的蒸汽压，以及预测的正常沸点（NBT）和预测的临界常数（这些预测依赖于蒸汽压数据）。临界常数通常是建立状态方程（EOS）所必需的。基于eos的模型可以提供化合物热物理性质的估计，以帮助设计工艺和设备。一种超灵敏、定量、痕量动态顶空分析样品称为多孔层状开管冷冻吸附（PLOT-cryo），用于测量这些化合物的蒸汽压。与更传统的蒸汽压测定技术相比，PLOT-cryo提供了较短的实验时间（几分钟对几天）。此外，PLOT-cryo具有稳定不稳定溶质的固有能力，因为收集是在降低的温度下进行的。所测得的蒸汽压比具有相似分子质量的正二十烷的蒸汽压低约2个数量级。因此，这些分子的极性差异一定对蒸汽压产生了巨大的影响。蒸汽压测量以克劳修斯-克拉珀龙（或范霍夫）方程图的形式表示。还给出了在接近环境条件（25℃）时的预计蒸汽压。Elsevier B.V.出版
The quest for a reliable means to detect cannabis intoxication with a breathalyzer is ongoing. To design such a device, it is important to understand the fundamental thermodynamics of the compounds of interest. The vapor pressures of two important cannabinoids, cannabidiol (CBD) and Delta(9)-tetrahydrocannabinol (Delta(9)-THC), are presented, as well as the predicted normal boiling temperature (NBT) and the predicted critical constants (these predictions are dependent on the vapor pressure data). The critical constants are typically necessary to develop an equation of state (EOS). EOS-based models can provide estimations of thermophysical properties for compounds to aid in designing processes and devices. An ultra-sensitive, quantitative, trace dynamic headspace analysis sampling called porous layered open tubular-cryoadsorption (PLOT-cryo) was used to measure vapor pressures of these compounds. PLOT-cryo affords short experiment durations compared to more traditional techniques for vapor pressure determination (minutes versus days). Additionally, PLOT-cryo has the inherent ability to stabilize labile solutes because collection is done at reduced temperature. The measured vapor pressures are approximately 2 orders of magnitude lower than those measured for n-eicosane, which has a similar molecular mass. Thus, the difference in polarity of these molecules must be impacting the vapor pressure dramatically. The vapor pressure measurements are presented in the form of Clausius-Clapeyron (or van't Hoff) equation plots. The predicted vapor pressures that would be expected at near ambient conditions (25 degrees C) are also presented. Published by Elsevier B.V.