| 
   tR = Retention time, K’= Capacity factors,  T =  Tailing factor, Rs = Resolution.
  |  | Level | tR | K’ | T | (Rs) |  
  | A: pH of mobile phase |  
  | 3.2 | -0.2 | 2.2 | 2.5 | 1.51 | 2.37 |  
  | 3.5 | 0 | 2.4 | 2.6 | 1.53 | 3.0 |  
  | 3.7 | 0.2 | 2.6 | 2.2 | 1.58 | 2.35 |  
  | S.D (n=6) |  | 0.2 | 0.212132 | 0.036056 | 0.01 |  
  | B: Flow rate (mLmin-1) |  
  | 0.8 | -0.2 | 2.6 | 2.1 | 1.56 | 2.32 |  
  | 1 | 0 | 2.4 | 2.6 | 1.53 | 3.0 |  
  | 1.2 | 0.2 | 2.2 | 2.5 | 1.51 | 2.37 |  
  | S.D (n=6) |  | 0.2 | 0.282843 | 0.025166 | 0.026458 |  
  | C: Percentage of water in mobile phase (V/V) |  
  | 90/10 | -20 | 2.6 | 2.7 | 1.52 | 2.39 |  
  | 70/30 | 0 | 2.4 | 2.6 | 1.53 | 3.0 |  
  | 80/20 | -10 | 2.2 | 2.4 | 1.57 | 2.32 |  
  | S.D (n=6) |  | 0.2 | 0.212132 | 0.026458 | 0.035119 |  
  | C: Wavelength (nm) |  
  | 210 | -5 | 2.5 | 2.7 | 1.52 | 2.39 |  
  | 215 | 0 | 2.4 | 2.6 | 1.53 | 3.0 |  
  | 220 | 5 | 2.3 | 2.5 | 1.59 | 2.33 |  
  | S.D (n=6) |  | 0.141421 | 0.141421 | 0.037859 | 0.03 |    |