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

Table 1

Recovery and matrix effect for the analytes in human plasma (n=3).

Analyte	Nominal concentration (ng/mL)	Recovery		Matrix Effect
		Mean ± SD	RSD	Mean ± SD	RSD
		(%)	(%)	(%)	(%)
MTX	10	92.76 ± 2.50	2.70	116.38 ± 1.33	1.15
	500	97.87 ± 4.81	4.92	117.60 ± 7.07	6.01
	5000	92.47 ± 8.18	8.85	116.07 ± 1.26	1.08
7-OH-MTX	10	97.61 ± 4.69	4.80	102.96 ± 9.08	8.82
	500	95.17 ± 3.51	3.69	97.90 ± 7.28	7.42
	5000	91.45 ± 4.27	4.67	99.57 ± 4.94	4.96
IS	500	100.50 ± 6.16	6.13	116.24 ± 3.06	2.63