Figure 1

An example of a metabolite profile. The results of quadrupole GC-QUAD-MS total ion chromatogram of different tissues of tomato (Lycopersicon esculentum) are shown. (a-c) Complete chromatogram (12.0-50.0 min). (d-f) An illustration of sample complexity and analyte range, by a representative expansion of the chromatograms shown in (a-c) for the region 26.3-28.2 min (highlighted). Tissues are: (a,d) tomato source leaf; (b,e) green fruit (30 days after flowering, DAF); (c,f) red fruit (60 DAF). Major peaks in the expanded region are identified directly on the chromatogram; *indicates novel metabolites detected within tomato fruit extracts compared to tomato leaf extracts. This figure illustrates clearly the problem of overloading, as sugars accumulate to high levels in red fruits, demonstrating the importance of measuring every metabolite at a concentration wherein the peak area is proportional to the metabolite concentration. Reproduced with permission from [47], which contains further details of the method and of the metabolites identified.