A Rapid Method for Determination of Some Phenolic Acids in Brazilian Tropical Fruits of Mangaba ( Hancornia speciosa Gomes ) and Umbu ( Spondias tuberosa Arruda Camara ) by UPLC

A rapid chromatographic method for the determination of six phenolic acids (chlorogenic, ferulic, gallic, p-coumaric, protocatechuic and vanillic acids) by ultra performance liquid chromatography (UPLC), was developed and applied for Brazilian tropical fruits mangaba (Hancornia speciosa Gomes) and umbu (Spondias tuberosa Arruda Camara). A multivariate statistical experimental design was employed to optimize analytical conditions (solvent A, solvent B concentrations and flow rates). Samples were cleaned-up by solid-phase extraction (SPE) with different solvents (methanol and acetone) employing SPE cartridges (amine and octadecyl-silane). The method using dihydrogen potassium phosphate 5 mmoL as solvent A and 8% acetonitrile as solvent B presented limits of detection varying from 14 to 94 ng.mL, limits of quantification from 39 to 277 ng.mL-1 with 2 μL of injection volume while total run time for all six compounds was only 9.6 minutes. Higher recovery was obtained by extraction with methanol-acetone of 69.51% to 72.59% for protocatechuic acid and 69.58% to 126.31% for the chlorogenic acid. The concentrations of chlorogenic, p-coumaric and ferulic acids in mangaba extracts were 113.4, 32.1 and 1.5 μg.g-1, respectively while concentrations of chlorogenic, protocatechuic, gallic, vanillic, ferulic and p-coumaric acids present in umbu fruit were 118.9, 141.3, 3.5, 2.5, 2.2 and 1.8 μg.g-1, respectively.