Pesticide analysis in cannabis products

Pesticide residue analysis in cannabis has become a subject of growing interest in North America since recent legalization in Canada and decriminalization for medicinal or recreational use in most US states. To meet regulatory and quality control standards, cannabis products should be tested for both authorized and unauthorized pesticides. In Canada, testing requirements mandated by Health Canada stipulate pesticide contaminant limits of quantification values of 0.02-3.0 μg/g, 0.01-2.5 μg/g and 0.01-1.5 μg/g for cannabis dried flowers, oil and fresh plants, respectively. Sample preparation and clean up methods reported in the literature for pesticide analysis in cannabis products include liquid-liquid extraction, solid-phase extraction, solid-phase microextraction and QuEChERS whereas separation and detection methods include thin-layer chromatography, capillary electrophoresis, high-performance liquid chromatography and gas chromatography in combination with various detectors such as UV and mass spectrometers. Advantages and disadvantages of the various analytical methods used in pesticide analysis of cannabis products are evaluated in this review. Furthermore, challenges ahead and future directions are discussed.