Figure 5. Representative chromatograms of an extracted DBS sample obtained from JIA patient treated with MTX; (pg1–5): MRM chromatograms of individual MTXPGs; concentrations found were MTXPG1, 9 nmol/L; MTXPG2, 10 nmol/L; MTXP3, 15 nmol/L; MTXPG4, 10 nmol/L and MTXPG5, 7 nmol/L, respectively.
(MTX-total): Chromatogram after conversion of total MTXPGs to MTXPG1; total concentration found was 49 nmol/L.