Myburgh, Paul JosefKemp, GerdusForbes, Patricia B.C.2022-10-142022-10-142021-11Myburgh, Paul; Kemp, Gerdus and Forbes, Patricia. Selective Solid-Phase Extraction Using Molecularly Imprinted Polymers for the Analysis of Target Pesticides in Cannabis Bud. South African Journal of Chemistry 2021, vol. 75, no. 1, pp.142-149. http://dx.doi.org/10.17159/0379-4350/2021/v75a17.1996-840X (online)0379-4350 (print)10.17159/0379-4350/2021/v75a17https://repository.up.ac.za/handle/2263/87715A molecularly imprinted solid-phase extraction (MISPE) procedure was developed for the GC-MS analysis of four high priority pesticides (atrazine, terbuthylazine, acetochlor and alachlor) in a cannabis bud sample matrix. The study demonstrated that the synthesised polymer had a high affinity and good selectivity for either chloroacetamide or triazine classes of pesticide used as a template molecule during the molecularly imprinted polymerisation reaction. The MISPE procedure was optimised in terms of loading, washing and elution fractions utilising a range of aqueous methanol solutions for optimal recovery and minimal matrix interferences. The optimal wash fraction was 20% (v/v) methanol in an aqueous solution, whilst 70% (v/v) was used for the elution fraction. The selectivity, accuracy and recovery of the MISPEs were verified using a synthesised non-imprinted polymer and a commercial C18 cartridge as reference sorbents in comparative experiments. Approximately 3 g of the cannabis bud sample was spiked at a 0.05 mg/kg maximum residue limit (MRL) concentration. The recovery of the four selected pesticides extracted from the spiked samples ranged between 76.4-85.0% when utilising the optimised MISPE methods, compared to 91.6-96.9% for the C18 SPE. However, the use of the MISPE resulted in enhanced selectivity, as evidenced by GC-MS analysis, due to the extraction of less matrix interferences. Therefore, it can be concluded that the MISPE is a viable pre-treatment method for selective pesticide analysis in cannabis flowers using GC-MS when selectivity is valued for the extraction of target pesticides from a complex sample matrix.en© The Author(s) Published under a Creative Commons Attribution 4.0 International Licence (CC BY 4.0).Molecularly imprinted solid-phase extraction (MISPE)Molecularly imprinted polymerSolid-phase extractionCannabisPesticidesAtrazineTerbuthylazineArticle