Figure 2.
LC chromatograms with nine channels of SRM ion traces (each SRM represents one substrate, one product or one internal standard): (a) Healthy individual specimen after acetonitrile mediated protein precipitation and (b) the same chromatogram combined with the steady infusion of GAA/GLA/IdA products and internal standards. The chromatogram in panel (c) shows the same specimen after acetonitrile protein precipitation. The sample volume was diluted to the initial mobile phase solvent composition. Panel (d) shows an identical LC run which was combined with steady infusion of GAA/GLA/IdA products and internal standards. The dashed lines indicate the main ion suppression regions.