Figure 6.

Correlations networks calculated from the pair-wise RV coefficients matrix from Test #1 (a) with spiked and non-spiked samples or with native urine samples only (b) and from Test #2 (c). Node labelling: N NMR platforms, Q QTOF mass spectrometer, O orbitrap mass spectrometer, T TOF mass spectrometer. The P or N appended to the mass spectrometer identifier number denotes positive or negative ionization mode, respectively. Node shapes: hexagon for nuclear magnetic resonance platforms, ellipse for mass spectrometers. The node size is proportional to the number of features retained by each instrument. The node colour from black to white indicates an increasing node degree (number of edges per node). The edges represent the RV coefficient values, with cut off values ≥0.791 in Test #1 and ≥0.708 in Test #2). At this cut off level, O3P was excluded from the Test #2 network (b) Martin, JC., Maillot, M., Mazerolles, G. et al. Can we trust untargeted metabolomics? Results of the metabo-ring initiative, a large-scale, multi-instrument inter-laboratory study. Metabolomics 11, 807–821 (2015). Copyright 2014 Springer Nature.