Forensic analysis of plant based drugs of abuse by DART-MS

Many plant species around the world are known to contain various psychoactive compounds. Due to their effects when consumed, many of these plants are used as a part of religious and ritualistic practices in many different cultures. As with any psychoactive compounds, these plants have the potential to be used in a recreational manner. In the United States, plant based drugs of abuse, such as marijuana, have become commonly abused substances. Although marijuana is currently regulated by the federal government, many of the plant materials containing potential drugs of abuse are not, and can be purchased legally from various online sources. The goals of this research were to develop methods for the analysis of a wide variety of plant based drugs of abuse by Direct Analysis in Real Time-Mass Spectrometry (DART-MS) and to apply the methods in an effort to differentiate between multiple strains of a single seed species. DART is an ambient ionization technique that allows for rapid analysis of samples while eliminating the need for sample preparation considerations for many applications. Analytes of interest can be detected within the complex plant matrix of ground up seeds, with no need for further extraction or isolation of the analytes. For this study, fourteen different seed samples, including twelve different species, reported to have psychoactive effects on the user were obtained and analyzed. Physical examination was performed, in which average measurements were obtained to describe the length, width, thickness, and mass of each seed species, followed by analytical analysis by DART-MS. The seeds were prepared for analysis by DART-MS by grinding to expose the middle of the seed containing the analytes of interest, and embedding the powder onto QuickStrip(TM) cards (IonSense, Inc.). To optimize the method for analysis, three different DART carrier gas temperatures (250°C, 300°C, and 350°C) were investigated for each seed sample by considering the signal to noise ratio, ion abundance, and presence of the analyte of interest at each source temperature using a single quadrupole mass spectrometer. The analytes detected were then subjected to MS(n) fragmentation in a quadrupole ion trap to confirm the identity of the analytes being detected. Fragmentation patterns were then compared to fragmentation patterns reported in the literature through methods such as chemical ionization, atmospheric pressure chemical ionization, and electrospray ionization. Thirteen of the fourteen seed samples were known to contain compounds with psychoactive properties. One of the species contained no known hallucinogenic compounds, however it was reported to have psychoactive effects when ingested or smoked. Protocols were developed for each sample and the identification of the analytes of interest was successful in twelve of the fourteen samples. DART-MS is a powerful technique for the detection and identification of a variety of plant based drugs of abuse, including tetrahydrocannabinol, lysergic acid amide, and numerous others. The ability to rapidly analyze a large number of samples makes DART-MS a technique with great potential in forensic laboratory settings, such as forensic drug analysis, where case backlog is often an area of concern. The majority of the samples explored in this study are not considered common substances of abuse. However, as their abuse is becoming more common, the high throughput nature of the analytical methods and techniques discussed will become increasingly important