Study of the proof for marihuana smoking by gas chromatographic analysis

为了证明吸食大麻，我们尝试了一种测定唾液和尿液中^9-四氢大麻酚(THC)的新方法。标准THC是从岛根县种植的大麻叶中提取的。我们建立了一种带有电子捕获脱向器(ECD)的气相色谱(GC)方法，该方法使用反应柱前进样器来测定唾液和尿液中的THC。用正己烷提取1毫升唾液或尿液。分别用氢氧化钠和盐酸溶液洗涤后，在氮气中蒸发正己烷层。溶解在乙酸乙酯和含THC残留物中的残留物为五氟丙酸(PFP)衍生物。以p，p‘-DDT为内标。GC/ECD法检测THC/PFP的灵敏度为1 ng/ml，在5~200 ng/ml范围内线性关系良好，唾液和尿液中THC的回收率分别为84%和%。我们对吸食一支Merihuana香烟的男性进行了实验吸烟检测，这些人的唾液和尿液中含有相当于10毫克THC的0.5克大麻叶。吸烟模型大鼠L吸烟后，唾液中THC浓度在吸烟后h为58.3~250.0 ng/m l，2 h为79.5~156.3 ng/m l，4 h后下降至34.1~74.1 ng/m l。另一方面，即使可以检测到THC，尿中THC的水平也很低，而且是微量的。总之，唾液中THC的毛细管GC/ECD分析将有助于检测大麻滥用者。

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.