Application of Ambient Ionization Mass Spectrometry for the Screening of Pesticide Contaminants on Cannabis Plant Materials.

As ambient ionization mass spectrometry is increasingly used for screening due to its ability to rapidly detect trace-level contaminants, this study developed a direct analysis in the real-time-mass spectrometry (DART-MS) method to investigate pesticides commonly used in Cannabis cultivation. While 108/113 pesticides were detected by the DART-MS method, evaluation of instrumental parameters revealed that the positive-ionization mode and a gas temperature of 350 °C were most effective for detecting pesticides. Experiments investigating major pesticide fragments and determining the lowest concentration at which the pesticide could be detected were also performed. Analysis of Cannabis plant materials spiked or treated with pesticides during cultivation demonstrated the applicability of this method to actual samples. The results of this study reveal that DART-MS can successfully screen for pesticide residues in Cannabis and serve as a qualitative screening tool to inform subsequent quantitative analyses.