On-line identification of minor flavones from sugarcane juice by LC/UV/MS and post-column derivatization

this work describes the on-line characterization of minor flavones from sugarcane (saccharum officinarum) juice by high-performance liquid chromatography coupled to diode array uv detection and mass spectrometry (lc/uv/ms) using atmospheric pressure chemical ionization-collision-induced dissociation (apci-cid-ms/ms) and post-column derivatization using uv shift reagents. hplc-uv analysis with shift reagents provided information about the substitution pattern in the flavonoid skeleton and, combined with ms data, these techniques allowed for the on-line identification of five "garapa" flavones: luteolin-8-c-glucosyl-7-o-glucuronide; tricin-7-o-neohesperoside-4'-o-rhamnoside; tricin-7-o-methylglucuronate-4'-o-rhamnoside; tricin-7-o-methylglucuronide; swertisin, while four other compounds were partially identified as glycosylflavones. only swertisin (7-o-methylapigenin-6-c-glucoside) was reported previously in sugarcane molasses.