Direct and interference-free determination of thirteen phenolic compounds in red wines using a chemometrics-assisted HPLC-DAD strategy for authentication of vintage year

In the present work, a novel chemometrics-assisted analytical strategy that combines three-way high performance liquid chromatography-diode array detection (HPLC-DAD) data with a second-order calibration method based on the alternating trilinear decomposition (ATLD) algorithm was developed for direct, accurate and simultaneous determination of thirteen phenolic compounds in complex red wine samples without an intricate clean-up step. All analytes were rapidly eluted out (7.5 min) under a simple gradient LC-separation and then detected in a multi-channel UV window. With the aid of the prominent second-order advantage of the ATLD algorithm, four common HPLC problems, i.e. solvent peaks, peak overlaps, unknown interferents and baseline drifts, could be mathematically calibrated, enabling pure signals of analytes to be extracted out from interference-heavy but information-rich HPLC-DAD profiles. The new strategy could avoid the loss of analytes of interest to significantly improve the analytical accuracy. Validation parameters, i.e. recovery (97.7-104%), precision (RSD < 7.1%), matrix effect, limits of detection (LODs, 0.02-0.27 mu g mL(-1)) and limits of quantitation (LOQs, 0.06-0.82 mu g mL(-1)) of thirteen analytes, were surveyed and further confirmed by the LC-MS/ MS method. Based on the indexes of phenolic compositions in wines, pattern recognition methods, i.e. principal component analysis and linear discriminant analysis (PCA-LDA), were applied for distinguishing wines of different storage years, and the discriminant accuracies were higher than 90%, which proved that this chemometrics-assisted HPLC-DAD strategy was an excellent method for direct and accurate determination of phenolic compositions in complex wine samples as well as the authentication of vintage year.