Level K’ T (Rs)
A: pH of mobile phase
2.8 -0.2 3.8 1.39 2.4
3 0 3.9 1.43 2.3
3.2 0.2 3.6 1.4 2.2
Mean ± S.D (n=6) 3.9 ± 0.2 1.4 ± 0.02 2.3 ± 0.1
B: Flow rate (mL/min)
0.6 -0.2 3.8 1.45 2.32
0.8 0 3.9 1.43 2.36
1.0 0.2 3.6 1.42 2.37
Mean ± S.D (n=6) 4.3 ± 0.2 1.4 ± 0.01 2.3 ± 0.0
C: Percentage of water in mobile phase (V/V)
35 -5 4.6 1.42 2.38
40 0 3.9 1.43 2.36
45 5 4.5 1.46 2.33
Mean ± S.D (n=6) 4.3 ± 0.0 1.4 ± 0.02 2.3 ± 0.0
D: Wavelength (nm)
220 -5 3.5 1.52 2.5
225 0 3.9 1.43 2.36
230 5 3.4 1.55 2.3
Mean ± S.D (n=6) 3.3 ± 0.1 1.5 ± 0.0 2.4 ± 0.1
K’=Capacity factors, N=Theoretical plates, T=Tailing factor Rs=Resolution
Table 6: Robustness of the method for captopril (n=6).