The testing of whole blood samples for tetrahydrocannabinol (Δ-9-THC) consumption is routine and has been around for many decades. As more isomers of Δ-9-THC become available on the market, testing becomes more complicated, and novel methods are needed to achieve isomeric resolution. One such isomer, Δ-8-THC, is federally unregulated in the United States and readily available for purchase in many stores. This compound forms its own hydroxylated and carboxylated metabolites, (11-OH-Δ-8-THC and Δ-8-THC-COOH), that must be chromatographically resolved from their isomeric metabolites.
An LC-MS/MS method was successfully developed on a Raptor FluoroPhenyl 100 x 3.0 mm, 2.7 μm column for reliable and accurate testing of Δ-8/9-THC isomers and isomer metabolites in whole blood. The method was determined to be quick, rugged, and sensitive enough to meet reporting guidelines for clinical and forensic toxicology laboratories.
