Table 4

Stability of stock solutions

SamplesConcentration (ng/mL)Time (day)Detected concentration (n=5) (ng/mL)RSD (%) (n=5)RSD (%) (n=15)
ODV20020.36 (1.29)6.318.07
4518.60 (2.22)11.91
9019.31 (28.31)1.47
2000198.75 (10.76)5.426.57
45193.36 (18.83)9.73
90206.39 (4.92)2.39
7500743.64 (36.43)4.99.37
45751.00 (12.51)1.67
90751.77 (20.99)2.79
VEN20020.35 (1.13)5.578.58
4518.77 (1.91)10.2
9019.41 (1.80)9.29
2000207.41 (13.4)6.466.17
45203.41 (19.17)9.42
90206.40 (2.62)1.27
7500770.85 (43.01)5.589.52
45758.00 (14.98)1.98
90755.67 (25.66)3.4
  • ODV, O-desmethylvenlafaxine; RSD, relative SD; VEN, venlafaxine.