Optimization strategy and validation of one chromatographic method as approach to determine the phenolic compounds from different sources.

We have designed a novel working strategy to optimize a unique chromatographic method consisting of diode array detection for the analysis of the most representative phenolic compounds from different food sources. The simultaneous inclusion of standard phenolic compounds, phenolic compounds isolated from food sources and representative real extracts as an ultimate test in analysis has allowed to establish, for the first time, a unique liquid gradient to serve as an excellent medium for the investigation of phenolics in samples from different food sources. Under the optimized conditions, 21 commercially available phenolic compounds and 25 commercially unavailable phenolic structures were analyzed in less than 30 min. The chromatographic method was designed as an alternative for the provisional identification of these compounds before their full characterization. The optimized chromatographic method was carefully validated for precision and accuracy. A high reproducibility in the retention time (<2%), peak area and calibration slope (<5%) as well as recoveries higher than 95% were obtained in all cases. Consequently, the currently described method was successfully employed to study the phenolic compounds in the most representative food samples.