Fast saliva analysis by GC–MS with Cold EI and Open Probe Fast GC–MS with Cold EI for the detection of cannabis usage

Saliva is a body fluid that is much easier to collect and analyze than blood. Thus, saliva analysis for the detection of delta 9-tetrahydrocannabinol (delta 9-THC) can serve as a tool for law enforcement agents to detect cannabis consumption by drivers. Fast saliva analysis for the presence of delta 9-THC and/or cannabidiol (CBD) is described with both gas chromatography–mass spectrometry (GC–MS) with Cold electron ionization (EI) with good separation and in 10 min and/or with Open Probe Fast GC–MS with Cold EI in under 1 min full analysis cycle time. Saliva was taken directly from donors' tongues on a thin glass rod that was used “as is” for analysis. The saliva was thermally desorbed with a modified ChromatoProbe device inside the gas chromatograph (GC) injector and in an Open Probe (Agilent name QuickProbe) for its sub-1-min analysis. Cold EI is based on coupling of the GC and mass spectrometer (MS) with a supersonic molecular beam and on EI of vibrationally cold sample molecules during their flight through a contact-free ion source (thereby named Cold EI). A revised type of Open Probe Fast GC–MS on the bench is also described. Our saliva analysis was characterized by: Saliva can be collected in the field and transported to the lab for analyses “as is” without any sample preparation. Easy detection of cannabis consumption from cigarettes and/or other cannabis products. Distinction between the isomers delta 9-THC and CBD. Ultra-fast analysis in under 1 min using Open Probe Fast GC–MS with Cold EI.