Tetrahydrocannabinol（THC）

After hemp enters the body, its main component thc is quickly metabolized into 11 hydroxy tetrahydrocannabinol (thc-oh or 11-OH-THC) in the liver and other tissues, and further metabolized into 11-normethyl-9-carboxyl-thc (THC-COOH). These compounds have high lipophilicity and are excreted in urine in the form of glucuronate and free form of tetrahydrocannabinoic acid. The main target of cannabis analysis in vivo is the metabolite THC-COOH. The detection of THC-COOH can be used as direct evidence of cannabis smoking. The detected concentration is mainly determined by the dose and time after smoking. Due to the rapid absorption process, the concentration of THC or metabolites is generally not measured during cannabis smoking.