Analysis of phenolic glycosides and saponins in Primulaelatior and Primulaveris (primula root) by liquid chromatography, evaporative light scattering detection and mass spectrometry

This paper describes the first liquid chromatographic method suitable for the simultaneous determination of bioactive compounds, saponins and phenolic glycosides, present in Primula elatior and Primula veris, including the NMR data of primulaverin and primeverin. Optimum separations were obtained with a Synergi 4 μm Fusion RP 80 Å column, using 0.025% TFA in water and 5% acetonitrile in methanol as mobile phase. Saponins were detected by evaporative light scattering detection (ELSD), whereas the phenolic glycosides were monitored by UV at 210 nm. The method was validated for repeatability (σrel ≤ 4.5%), precision (intra- and inter-day variation ≤5.0%), accuracy (recovery ≥97.1%) and sensitivity (LOD ≤22 ng (UV) and ≤38 ng (ELSD) on-column, respectively). LC–MS experiments in negative APCI mode allowed a final peak assignment. Both Primula species could easily be differentiated by their saponin pattern. The total saponin content was highest in P. veris roots (max. 14.9%), the aerial parts or P. elatior contained significantly less amounts; primeverin (0.64–1.42%) showed to be the most dominant phenolic glycoside.