MAR 28, 2019 9:00 AM PDT

Analysis of Cannabis for Pesticides and Mycotoxins Using UPLC-MS/MS and GC-MS/MS

C.E. Credits: P.A.C.E. CE Florida CE
  • Principal Scientist, Scientific Operation, Waters Corporation
      Marian has over 17 years of experience working as an analytical chemist supporting applications in the food and environmental, pharmaceutical and materials science industries. She has held several senior scientist positions developing quantitative analytical methods to meet regulatory requirements. Marian holds a Ph.D. in analytical chemistry from Cork Institute of Technology, Ireland. Currently, the focus of Marian's work is in the development of robust analytical methods to meet regulatory compliance in cannabis safety testing. She considers it an honour to work with other scientists to solve analytical problems using chromatography, sample preparation and mass spectrometry technologies.


    Quantitative methods for residual pesticides and mycotoxins analysis in cannabis should provide reliable coverage and robust methodology for the entire list of analytes to fulfill the state mandated safety tests.

    The detection sensitivity and specificity offered by LC/MS/MS is advantageous for determining trace levels of most pesticides and mycotoxins in complex matrices. However, not all pesticides ionize efficiently by conventional ionization techniques such as electrospray or atmospheric pressure chemical ionization.  In such cases, trace level detection of pesticides in the presence of a highly complex matrix can be challenging and variable leading to inconsistencies in the results.  The combination of LC-MS/MS and GC-MS/MS utilises the advantages of both techniques and can provide quantitative and confirmatory analysis of challenging compounds that can be analysed by either approach.

    In this study, a comprehensive evaluation of pesticide analysis in cannabis flower matrix was performed using both analytical techniques. Sample extraction procedures were optimized and a simple dispersive SPE method was used for clean-up of the initial acetonitrile extract. 

    Methods met the regulatory requirements for cannabis pesticide residues and mycotoxins testing in the State of California. Overall method performance was evaluated by assessing recovery, matrix suppression, linearity, and sensitivity. The results from accuracy, precision and evaluation of matrix effects will be discussed. 

    Learning Objectives: 

    1. Workflow for the analysis of pesticide residues and mycotoxins in cannabis using both LC-MS/MS and GC-MS/MS
    2. Sample preparation using dSPE cleanup to reduce matrix effects for trace level detection of pesticides in cannabis. 

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