Figure 4.

Separation and identification of three flavonoids, cyanidin, luteolin, and kaempferol, with the same molecular formula of the positive ion (C₁₅H₁₁O₆⁺) in platform 8. The compounds were identified based on their MS/MS spectra, which were compared with reference spectra from publicly available databases [35]. Based on the retention time of cyanidin 3-O-glucoside, also present in the mixture, the feature appearing at RT 1.77 min in platform 7 and 3.5 min in platform 8 was identified as an in-source fragment (cyanidin ion).