A validated method for the quantification of mitragynine in sixteen commercially available Kratom (Mitragyna...

The recent rise in the recreational use of plant-based "legal highs" has prompted the development of methods for the identification of the bulk material, and quantification of their psychoactive components. One of these plants is Mitragyna speciosa, commonly referred to as Kratom. While traditional use of this plant was primarily for medicinal purposes, there has been a rise in its recreational use, and as a self-prescribed medication for opioid withdrawal. Although Kratom contains many alkaloids, mitragynine and 7-hydroxymitragynine are unique psychoactive biomarkers of the species, and are responsible for its psychoactive effects. A rapid validated method for the quantification of mitragynine in Kratom plant materials by direct analysis in real time-high-resolution mass spectrometry (DART-HRMS) is presented. It has a linear range of 5-100 μg mL^-1, and a lower limit of quantification of 5 μg mL^-1. The protocol was applied to determination of the mitragynine content of 16 commercially available Kratom plant products purchased online. The mitragynine amounts in these materials ranged from 2.76 to 20.05 mg g^-1 of dried plant material. The utilization of DART-HRMS affords a mechanism not only for the preliminary identification of bulk plant material as being M. speciosa-derived (with no sample preparation required), but also provides the opportunity to quantify its psychoactive components using the same technique.