title: Improved Quantification of Free and Ester-Bound Gallic Acid in Foods and Beverages by UHPLC-MS/MS.
abstract: Hydrolyzable tannins are measured routinely during the characterization of food and beverage samples. Most methods for the determination of hydrolyzable tannins use hydrolysis or methanolysis to convert complex tannins to small molecules (gallic acid, methyl gallate, and ellagic acid) for quantification by HPLC-UV. Often unrecognized, analytical limitations and variability inherent in these approaches for the measurement of hydrolyzable tannins include the variable mass fraction (0-0.90) that is released as analyte, contributions of sources other than tannins to hydrolyzable gallate (can exceed >10 wt %/wt), the measurement of both free and total analyte, and lack of controls to account for degradation. An accurate, specific, sensitive, and higher-throughput approach for the determination of hydrolyzable gallate based on ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) that overcomes these limitations was developed.
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy , 833 South Wood Street, Chicago, Illinois 60642, United States.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Newsome
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy , 833 South Wood Street, Chicago, Illinois 60642, United States.
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, University of Illinois College of Pharmacy , 833 South Wood Street, Chicago, Illinois 60642, United States.
authors.forename: Richard B
authors.initials: RB
authors.lastname: van Breemen
mesh_terms: D001628:Beverages / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004610:Ellagic Acid / Q000737:chemistry; D005707:Gallic Acid / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D004610:Ellagic Acid; D005707:Gallic Acid
keywords: MS/MS; UHPLC; electrospray; ellagic acid; ellagitannins; gallic acid; gallotannins; hydrolyzable tannins; methanolysis; methyl gallate