Development of an analytical method for detection and quantification of cannabis and cannabinoid analogues in urine

Abstract

Cannabis is a drug mainly consumed for its euphoric effects; users may become happy, careless and relaxed. The direct effects of cannabis in sports are performance decreasing, but cannabis can be used as a doping agent due to its relaxing properties. For these reasons, cannabinoids are prohibited in sports during competition by the World Anti-Doping Agency (WADA).

In the context of the fight against doping, urine is screened for the metabolite THC-COOH (11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid or carboxy-THC) with a cut-off of 15 ng/mL as a reporting limit for adverse analytical finding. This criterion does not fully allow a differentiation of in- or out-of-competition abuse and might not distinguish between active and passive inhalation.

The presence of THC (Delta-9-tetrahydrocannabinol) and THC-OH (11-hydroxy-delta9-tetrahydrocannabinol) metabolite in urine has been proposed as indicators for recent cannabis use. Thus the need to develop and implement a method for detection and quantification of THC, THC-OH, and THC-COOH in urine appeared to be necessary in an anti doping laboratory. High sensitivity and specificity are required in such analytical method and for that purpose a GC-TSQ (Gas chromatography-triple quadrupole) was used.

A method for the detection of the compounds was developed regarding GC-TSQ parameters, sample extraction and conditions of hydrolysis. The method was validated for specificity, but, due to several problems, it was not possible to fully validate this new method. The preliminary results obtained during this project suggest that the method should be further validated.