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

Figure 2

The product ion plots and fragmentor structures of MTX, 7-OH-MTX, and IS in positive mode. (a) MTX; (b) 7-OH-MTX; (c) IS.

(a)

(b)

(c)