UPLC/FT-ICR MS-based high-resolution platform for determining the geographical origins of raw propolis samples

In this study, we demonstrate a high-resolution 15 Tesla Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry coupled with a reverse-phase ultra-performance liquid chromatography (RP-UPLC) system for determining the geographical origins of raw propolis samples. The UPLC/FT-ICR MS-based high-resolution platform was validated on the ethanol-extracted propolis (EEP) from various propolis raw materials originating from different countries (i.e., Argentina, Brazil, China, and Korea) to determine the geographical origins of the propolis and the origin-specific key compounds. Based on approximately 8000 molecular features extracted from UPLC/FT-ICR MS datasets, a partial least squares-discriminant analysis (PLS-DA) plot showed distinct separations among propolis samples from four different origins. Key propolis components contributing to the discrimination of Korean propolis from Brazilian and Chinese propolis were identified and classified into five subgroups (i.e., flavonoids, phenols, terpenoids, fatty acids, and others). This analysis revealed the characteristic features of the different propolis samples, and this analytical platform can be further used to determine the geographical origins and to assess the quality of the commercial products.