Determination of Enzymatic Hydrolysis Efficiency in Detection of Cannabis Use by UPLC-MS-MS

Abstract

Cannabis is still the most widely used illegal plant in the world. However, cannabis use is prohibited in many countries. After cannabis use, Δ9-tetrahydrocannabinol is metabolized in the liver to 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) and most undergo glucuronidation. THC-COOH and THC-COOH glucuronide are excreted in the urine. The total concentration of THC-COOH in the urine sample is measured to determine cannabis use. The total concentration is determined after enzymatic or alkaline hydrolysis. In this study, comparing enzymatic hydrolysis efficiency is presented comprehensively together with the method developed for the determination of total THC-COOH in the urine. Also, the method was validated according to the European Medicines Agency Guidelines on bioanalytical method validation. The method has rapid hydrolysis time (20 min), rapid analysis time (5 min) and simple sample preparation. The lower limit of quantitation of the developed method was 1 ng/mL for THC-COOH. The calibration curve of THC-COOH was between 1 and 2,000 ng/mL with a correlation coefficient >0.99. Also, the method was applied to real patient's urine. We think that the results will provide a new perspective on enzymatic hydrolysis optimization studies.