Miniaturized and automated analysis of pesticides in Cannabis sativa L. flowering tops by means of a robotic platform coupled to liquid chromatography-tandem mass spectrometry

: Cannabis sativa L. plant has acquired significant attention in recent years considering that numerous countries around the world are legalizing it for medical uses or recreational purposes. Due to its increasing popularity, farmers are particularly prone to use pesticides such as insecticides, acaricides, and fungicides in order to eliminate, repel, or minimize aphids, spider mites, and thrips, respectively. Accurate determination of pesticide residues in cannabis plants is mandatory to safeguard consumer health. This research study is focused on the employment of a robotic platform online coupled to UHPLC-MS/MS instrument for the rapid screening of pesticides in Cannabis sativa L. flowering tops. The developed automated procedure required only 30 mg of dried sample and 200 μL of acetonitrile as unique extraction solvent. The total analysis time was 25 min per sample, including extraction cycle (10 min). The method was proved by defining the following figures of merit: intra- and inter-day repeatability, linearity range, limits of quantification (LoQs), recovery, and accuracy. The LoQs for all the analytes were of 0.005 μg g-1, except for aldicarb and boscalid compounds (0.01 μg g-1). Matrix-matched calibration curves showed good linearity over the range with coefficients of determination ≥ 0.9991. Recoveries ranged from 72.3 % to 116.2 % in accordance with 70-120 % allowed range by SANTE/11312/2021v2026 guidelines. The sample preparation greenness was assessed using sample preparation method of sustainability (SPMS) and analytical greenness metric (AGREEprep) tools, providing scores of 6.42 and 0.55 respectively, higher than those obtained for conventional QuEChERS workflow (3.79 and 0.16).