Macklai, Sabrina-Surveillance of Cannabis Use in Urine by Multisegment Injection-Capillary Electrophoresis-Electrospray Ionization-Triple Quadrupole-Mass Spectrometry (MSI-CE-ESI-QQQ-MS) (Dr. Philip Britz-McKibbin)

Surveillance of Cannabis Use in Urine by Multisegment Injection-Capillary Electrophoresis-Electrospray Ionization-Triple Quadrupole-Mass Spectrometry (MSI-CE-ESI-QQQ-MS)

In October of 2018,  the Canadian federal government legalized recreational cannabis. This newfound widespread availability of cannabis led to many researchers studying the public health effect of cannabis,  namely determining its therapeutic potential and negative drawbacks.

One way to approach this is through studying cannabis metabolism. The most routinely screened-for metabolites of cannabis,  referred to as cannabinoids,  are Δ9-tetrahydrocannabinol and cannabidiol. These are known for their psychoactive and therapeutic properties respectively. By studying the concentrations of these metabolites in cannabis users’ urine,  we can determine how metabolism differs per individual.

The gold standard for cannabis screening is urine screening using tandem liquid chromatography-mass spectrometry. However,  the gold standard is flawed in that the immunoassay has issues with bias and the confirmatory test,  while sensitive,  requires hours to run multiple samples with extensive sample preparation. 

Herein,  we proposed a novel screening platform for cannabis surveillance in urine that allows for targeted analysis of metabolites and a higher throughput. This platform is multi-segment injection-capillary electrophoresis-electrospray ionization-triple quadrupole-mass spectrometry (MSI-CE-ESI-QQQ-MS). Results reveal that MSI-CE-ESI-QQQ-MS can confidently detect cannabinoids at the confirmatory level (25 ng/mL). As this new interface does not require enzyme deconjugation and also employs multi-segment injection,  it can achieve a turnover of three minutes per sample. 

Thus,  this newly created platform can be used to screen for cannabis use for a wide variety of purposes. Beyond advancing our understanding of cannabis metabolism,  this platform is ideal for use in workplace drug testing and other situations where rapid and reliable results are required.