Development of an HPLC/Diode-Array Detector Method for Simultaneous Determination of Seven Hydroxy-Cinnamic Acids in Green Coffee

Abstract
A simple, rapid, sensitive, reproducible, and accurate reverse phase HPLC procedure is proposed for the determination of seven phenolic acids in green coffee samples. The sample preparation was simple, involving extraction, alkaline hydrolysis, and liquid/liquid extraction. The chromatographic separation was achieved using a reverse phase column Spherisorb ODS2 (5μm; 25.0 × 0.46 cm). Gradient elution was carried out using water-formic acid (19:1) (A) and methanol (B). The effluent was monitored by a diode-array detector and chromatograms were recorded at 320 nm. The detection limit value of the method was 0.09 μg/mL and the method was precise(CV%=0.5%; n=10). Recovery values of caffeic acid from spiked green coffee samples were between 88.3 and 93.2%.