Simultaneous Quantification of Methotrexate and Its Metabolite 7-Hydroxy-Methotrexate in Human Plasma for Therapeutic Drug Monitoring

Figure 3

The chromatograms of MTX, 7-OH-MTX, and IS under MRM mode: (a) blank sample; (b) blank plasma spiked with MTX (5 ng/mL); (c) blank plasma spiked with 7-OH-MTX (5 ng/mL); (d) blank plasma spiked with IS; (e) lower limit of quantification sample; (f) real sample collected at 44 h after the administration of MTX from one patient.

(a)

(b)

(c)

(d)

(e)

(f)