Study of the proof for marihuana smoking by gas chromatographic analysis

为了证明大麻吸食者吸食大麻，我们尝试了一种新的气相色谱法测定唾液和尿液中的^9-四氢大麻酚（THC）。从生长在岛根县的大麻叶中提取标准THC。建立了一种采用反应柱前进样器、电子捕获检测器（ECD）的气相色谱法测定唾液和尿液中THC的方法。用正己烷提取1 ml唾液或尿液。用氢氧化钠和盐酸的各溶液洗涤后，在氮气下蒸发正己烷层。溶解在乙酸乙酯中的残余物和含THC的残余物是五氟丙酸（PFP）衍生物。以p，p '-DDT为内标。THC/PFP的GC/ECD分析灵敏度为1 ng/ml唾液，线性范围为5 ~ 200 ng/ml。唾液和尿液中THC的回收率分别为84%和64%。我们已经检查了实验吸烟检测的唾液和尿液中的男子谁吸了一个单一的merihuana香烟，含有0.5克大麻叶相当于10毫克的THC。吸模型烟后1h唾液THC含量为58.3- 250.0ng/ml，2 h为79.5- 156.3ng/ml，4 h后下降至34.1- 74.1ng/ml。另一方面，尿液中的THC水平较低，即使可以检测到THC，也是微量的。结论：毛细管气相色谱/电子捕获检测器分析唾液中的THC可用于大麻滥用者的检测。

For the proof of marihuana smoking, we have tried a new gas chromatographic method for the determination of ^9-tetrahydrocannabinol(THC) in saliva and urine. standard THC was extracted from Cannabis leaves which grown in shimane Prefecture. We developed a gas chromatographic(GC) method with an electron capture defector(ECD) using a reaction pre-column injector for the determination of THC in saliva and urine. One milliliter of the saliva or urine was exrtacted with n-hexane. After washing with each solution of sodium hydroxide and hydrochloric acid, the n-hexane layer was evaporated under nitrogen gas. The residue dissolved in ethyl acetate and THC containing residue was pentafluoropropionic(PFP) derivatives. p,p'-DDT was used as internal standard. The GC/ECD analysis of THC/PFP had a sensitivity of 1 ng/ml of saliva and good linearity was observed on calibration curve in concentration range of 5 to 200 ng/ml. Recoveries of THC added to saliva and urine were 84 % and 64 %, respectively. We have examined experimental smoking for detecting in the saliva and urine of men who smoked a single merihuana cigarette that contained 0.5 g of cannabis leaves equivalent to 10 mg of THC. After smoking model cigarette, the THC levels in saliva were 58.3-250.0 ng/ml at l h, 79.5-156.3 ng/ml at 2 h, and declined at 34.1-74.1 ng/ml 4 h after. On the other hand the urinary THC levels were lower and trace amounts even if the THC can be detectable. In conclusion, the capillary GC/ECD analysis of THC in saliva would be useful for the detection of marihuana abusers.