Application of conventional UV, photodiode array (PDA) and fluorescence (FL) detection to analysis of phenolic acids in plant material and pharmaceutical preparations.

Free phenolic acids (PhAs) contained in methanolic extracts of Eleutherococcus senticosus roots and pharmaceutical preparations, deriving from this plant, were isolated by solid-phase extraction (SPE) and identified by reversed-phase high-performance liquid chromatography (RP-HPLC). To obtain precise, accurate and validated results of qualitative and quantitative analysis, ultraviolet (at lambda=254 nm), photodiode array (at lambda=254 and 280 nm) and fluorescence (at lambda(Ex)=230 or 265 nm and lambda(Em)=350 nm) detection was used. Additionally, the HPLC separation of PhAs on two different octadecyl sorbents: Hypersil (Shandon, UK) and Symmetry (Waters, USA) was performed. Eight PhAs: chlorogenic, protocatechuic, p-hydroxybenzoic, caffeic, vanillic, syringic, p-coumaric and ferulic, in different quantitative proportions, were identified, both in the roots of E. senticosus and pharmaceutical formulations examined.