Level K’ T (Rs)

A: pH of mobile phase

2.0 -0.2 4.8 1.39 2.4
2.5 0 4.5 1.43 2.3
3.0 0.2 4.2 1.4 2.2

Mean ± S.D (n=6)

4.5 ± 0.3 1.43 ± 0.020 2.3 ± 0.1

B: Flow rate (mLmin-1)

0.8 -0.2 4.1 1.45 2.32
1 0 4.2 1.45 2.36
1.2 0.2 4.4 1.42 2.37

Mean ± S.D (n=6)

4.3 ± 0.212 1.44 ± 0.015 2.36 ± 0.026

C: Percentage of water in mobile phase (V/V)

25 -5 4.6 1.42 2.38
20 0 4.3 1.43 2.36
15 5 4.5 1.46 2.33

Mean ± S.D (n=6)

4.36 ± 0.070 2.36 ± 0.025 2.36 ± 0.025

C: Wavelength (nm)

220 -5 4.5 1.42 2.38
225 0 4.3 1.43 2.36
230 5 4.4 1.45 2.32
Mean ± S.D (n=6) 4.3 ± 0.070 1.43 ± 0.015 2.36 ± 0.030
K’= Capacity factors, N = Theoretical plates, T = Tailing factor Rs=Resolution
Table 4: Robustness of the method.