Level K’ T (Rs)
A: pH of mobile phase
2.8 -0.2 17.3 1.71 5.3
3 0 17.7 1.73 5.5
3.2 0.2 17.2 1.78 5.35
B: Flow rate (mLmin-1)
0.8 -0.2 17.1 1.71 5.32
1 0 17.7 1.73 5.5
1.2 0.2 17.5 1.78 5.37
C: Percentage of water in mobile phase (V/V)
80/20 -5 17.1 1.70 5.39
75/25 0 17.7 1.73 5.5
70/30 +5 17.5 1.70 5.32
D: Wavelength (nm)
220 -5 17.7 1.72 5.39
225 0 17.7 1.73 5.5
230 5 17.1 1.79 5.32
K’= Capacity factors,  T =  Tailing factor, Rs = Resolution
Table 5: Robustness of the proposed method n=6.