Universidad Autonoma de Ciudad Juarez 1 article published in JoVE Biochemistry Semi-Targeted Ultra-High-Performance Chromatography Coupled to Mass Spectrometry Analysis of Phenolic Metabolites in Plasma of Elderly Adults Óscar A. Muñoz-Bernal1, Alma A. Vazquez-Flores1, Emilio Alvarez-Parrilla1, Nina R. Martínez-Ruiz1, Laura A. de la Rosa1 1Department of Chemical Biological Sciences, Universidad Autónoma de Ciudad Juárez The goal of this protocol is to detect phenolic metabolites in plasma using a semi-targeted chromatography-mass spectrometry method.