High performance liquid chromatographic determination of phenolic compounds in seed exudates of Festuca arundinacea and F. pratense

Derivatives of benzoic and cinnamic (caffeic, protocatechuic, vanillic, ferulic, p-coumaric, p-hydroxybenzoic and syringic) acids and 3,4-dihydroxybenzaldehyde in seed exudates of Festuca arundinacea cv. “Kora” and F. pratense cv. “Otava” have been separated and quantified on a Zorbax SB C18 Rapid Resolution™ column with linear gradient elution using a mobile phase containing acetonitrile and 0.5% acetic acid. The USP tailing factors were less than 1.15 for all peaks. Strictly linear calibration curves (r > 0.9997) with limits of detection of 90–880 nM were obtained for all analytes in the concentration ranges from units or tenths up to 600 µM. RP 105 and OASIS™ HLB polymeric sorbents have been shown to be the best of the tested sorbents for the separation and preconcentration of phenolic compounds from both plant materials. The solid-phase extraction procedures have been compared with classical liquid–liquid extractions and consistent results were obtained.