[Simultaneous determination of 6 phenolic acids in coffee beans by reversed-phase high performance liquid...

A method of reversed-phase high performance liquid chromatography coupled with diode array detection (HPLC-DAD) was established for the simultaneous determination of 6 phenolic acids in green coffee beans. These phenolic acids are caffeic acid, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,5-O-dicaffeoylquinic acid and 4,5-O-dicaffeoylquinic acid. The separation was achieved using a Kromasil C18 column (200 mm x 4.6 mm, 5 microm) under the gradient elution with the mobile phases of acetonitrile and 0.1% (v/v) formic acid/water. The 6 phenolic acids were well separated within 45 min. The recoveries were from 90.76% to 104.73% with the relative standard deviations between 0.7% and 3.9%. The method is simple, rapid and highly sensitive, suitable for the simultaneous determination of 6 phenolic acids and quality control of coffee beans.