Headspace solid-phase microextraction of pesticide residues in Cannabis samples

A headspace solid-phase microextraction method combined with gas chromatography-mass spectrometry was evaluated for the extraction and analysis of selected pesticides, namely alachlor, P-hexachlorocyclohexane, bromopropylate, carbaryl, diazinon, linuron, polychlorobiphenyl 209, permethrine and simazine in cannabis samples. Using a 100 gm PDMS fibre, compounds were directly extracted in the headspace mode at 150 degrees C for 5 min and desorption was performed in the GC injector in the splitless mode at 280 degrees C for 3 min. Pesticide analysis was achieved and method repeatability, given as the coefficient of variation, ranged between 2.4% for bromopropylate and 12.6% for linuron. The limits of detection obtained using single ion monitoring (SIM) were between 0.014 and 0.83 mg/kg, depending on the pesticide.