Determination of Pesticide and Mycotoxin Residues in Dried Cannabis Flower: LC-MS/MS and GC-MS/MS Methodology to Meet the Recommended AOAC Regulatory Requirements for US States and Canada

Introduction

Although cannabis products are legal for medicinal or recreational use in many US states and in Canada, there are currently no harmonized guidelines for pesticide and mycotoxin residue tolerances. Consequently, each state or nation with legalized cannabis has its own list of such contaminants with legal residue tolerance limits that may be quite different in each region. Moreover, AOAC has published Standard Method Performance Requirements (SPMRs) to describe the minimum recommended performance characteristics to be used to evaluate methods for determination of pesticides in cannabis.¹ AOAC has used the lowest tolerance level from any of the US states or Canada as the target action level for any proposed method with a recommended LOQ at 50% of the action level. These criteria are used for evaluation of validation study data for methods under consideration for AOAC Official Methods of Analysis; they also are commonly used as acceptance criteria for verification at user laboratories. The methodology presented in this application note is suitable, with a few exceptions, to determine pesticides and mycotoxins currently regulated by any of the US states or Canada at the AOAC-recommended LOQ. In their SMPR document, AOAC has also included twenty-nine pesticides that do not currently have a regulatory requirement in the US or in Canada. For these pesticides, the AOAC Cannabis working group has recommended an arbitrary target LOQ of 0.005 ppm (mg/kg).