Analysis of Hop Acids and Their Oxidized Derivatives and Iso-α-acids in Beer by Capillary Electrophoresis−Electrospray Ionization Mass Spectrometry García Villalba, Rocío Cortacero-Ramírez, Sonia Segura-Carretero, Antonio Martín-Lagos Contreras, José Antonio Fernández Gutiérrez, Alberto This study investigates the applicability of on-line coupling of capillary electrophoresis with electrospray ionization tandem mass spectrometry (CZE-ESI-MS) for the separation and characterization of α ¬and β-acids and oxidized hop acids from crude extracts of different hop varieties. CZE-ESI-MS with negative-ion electrospray ionization proved to be a suitable technique for the determination of these types of natural compounds and their oxidized derivatives. The CZE parameters (pH, concentration, and buffer type) and ESI-MS parameters (nature and flow rate of the sheath liquid, nebulizer pressure, drying gas flow rate, temperature, and compound stability) were optimized. The optimized method provides the potential for a fast qualitative determination of hop acids and their oxidation compounds. The method was also applied to the determination of iso-α-acids in beer. 2024-01-29T12:57:24Z 2024-01-29T12:57:24Z 2006-07-01 journal article https://hdl.handle.net/10481/87511 10.1021/jf060207x eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional ACS Publications