Improving Detection for Metal Sensitive Pesticides and Mycotoxins in Cannabis Flower

Similar to other crops, cannabis flower can contain contaminants that are harmful to humans, two of the most common being pesticides and mycotoxins. Low limits of detection are necessary for this type of contaminant testing. However, achieving limits of parts per billion can be challenging due to the complexities of cannabis as well as certain analyte properties. These analyte properties include poor ionization and chelation to metal surfaces. Recently, the commercial availability of inert columns has increased in order to address this issue with metal sensitive compounds seen in traditional stainless steel column hardware. In this work, a selection of pesticides and mycotoxins were chosen for evaluation with attention to both traditionally good and poor performing analytes. Two separate LC methods, one for pesticides and one for mycotoxins, were developed and used to compare traditional stainless steel to inert LC hardware for peak shape and sensitivity. Using >15% (w/w) THC content cannabis, samples were prepared using a simple dilute and shoot method. In-matrix calibration curves were prepared by post-spiking cannabis extracts with target analytes at various concentrations. Accuracy and precision were assessed. Improvement was notable in both peak shape and peak height when comparing out-of-the-box performance. Results show inert hardware provides a robust analytical solution to improve sensitivity for pesticides and mycotoxins.