Determination of phenolic acids in strawberry samples by means of fast liquid chromatography and multivariate curve resolution methods.

Use of Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) is evaluated in the analysis of nine phenolic acids, both in standards mixture samples and in strawberry juice samples, by liquid chromatography with diode array detection (LC-DAD). Chromatographic coelution problems either because of unknown matrix interferences or because of the increase of organic modifier to reduce chromatographic analysis times are investigated. pH (4.25) and proportion of organic modifier in acetonitrile-water ratios (11:89, v/v) used as mobile phases have been optimized for separation of mixture of nine phenolic acids. Results obtained in the resolution and quantitation of phenolic acids in standards mixture samples and strawberry samples at two proportions of organic modifier (11:89 and 40:60 acetonitrile-water (v/v) ratios) show that the proposed MCR-ALS approach reduces analysis times and solvent expenses and improves determinations in case of strong coelution. Limits on the use of MCR-ALS are investigated in the analysis of phenolic acids in strawberry samples.