Fig. 4. High-resolution IRMPD FTICR mass spectrum of a precursor ion [M—H] — with m/z 598.10626, detected in a sample extract of B. vulgaris seeds. Spectrum interpretation revealed that this precursor ion may be assigned to the previously known 60-isoferuloyl-gluconasturtin, [C H O NS –H] —. The precursor ion was photon-irradiated for 25 29 12 2 130 ms at 100% laser power. Note the formation of ions at m/z 193.05081 (error 0.93 ppm), 178.02727 (error 0.62 ppm) and 226.01813 (error 0.80 ppm), whose details are provided in the text. The proposed chemical structure of this last ion is shown in inset.