Fig. 5

Mass spectra of all-trans-β-Car extracted from non-labeled and ¹³C-labeled Arabidopsis plants. FTICR-MS showing two types of quasi-molecular ions of β-Car, [M]⁺ and [M + H]⁺, in a non-labeled (a) and a ¹³C-labeled (c) sample. Deviations from the expected mass (Δ) are given in parts per million (ppm). TQ-MS in the same non-labeled (b) and ¹³C-labeled (d) samples as in a and c. Overlapping mass peaks of [M]⁺ and [M + H]⁺ ions are regarded as [M + H]⁺ or [M]⁺ in the analysis of FTICR-MS and TQ-MS, respectively. Peak assignment of these data is summarized in Additional file 2: Tables S3–S6. Theoretical distribution of carotenoid isotopologs based on natural ¹³C abundance (~ 1.1%) is presented in Additional file 1: Fig. S8