A liquid chromatographic time-of-flight tandem mass spectrometric method for the comparative study of propolis aqueous and cyclodextrin extracts employing target and suspect screening

Green solvents are being studied for extracting bioactive compounds. In the present study, phenolic extracts of propolis were prepared employing water and aqueous β-cyclodextrin solution. A liquid chromatographic method coupled to time-of-flight (LC-QTOF-MS/MS) was developed and validated employing target and suspect screening. The method showed good linearity (R² > 0.9900) in the working range between 0.050 and 5 mg L^–1. and presented low limits of quantification (LOQs) and detection (LODs) over the ranges 0.050–0.100 mg L⁻¹ and 0.015–0.030 mg L⁻¹, respectively. The RSD values were lower than 6.8 % for intra-day and inter-day precision, demonstrating good precision. The matrix effect values were lower than 19.2 % for all the analytes indicating the low influence of the matrix in the determination. Overall, in the green extracts analyzed, 16 target bioactive compounds were determined and 24 suspects were tentatively identified. In terms of targeted analysis, the methanolic extract presented higher concentrations of phenolic compounds compared to the aqueous and β-cyclodextrin ones. Suspect screening revealed that marker compounds of poplar-type propolis were identified in all three extracts, highlighting the potential of green extraction solvents for the recovery of propolis bioactive compounds.