Determination of Fluoroquinolones in Pharmaceutical Formulations by Extractive Spectrophotometric Methods Using Ion-Pair Complex Formation with Bromothymol Blue
Table 2
Analytical characteristics of the proposed methods ().
Parameters
Proposed methods
Ofloxacin
Levofloxacin
Ciprofloxacin
Colour
Yellow
Yellow
Yellow
Wavelengths λmax (nm)
418
415
420
pH
3.3
3.5
3.4
Stability (h)
24
24
24
Shaking time (min)
2
2
2
Stoichiometric ratio
1 : 1
1 : 1
1 : 1
Beer’s law range (µg/mL)
1–35
0.5–25
0.5–25
Limit of detection, LOD (µg/mL)
0.105
0.101
0.084
Limit of quantitation, LOQ (µg/mL)
0.315
0.303
0.252
Molar absorptivity (L/mol.cm)
1.44 × 104
2.07 × 104
2.09 × 104
Sandell’s sensitivity (µg/cm2)
0.068
0.048
0.046
Regression equation (Y = bx + a), where Y is the absorbance, a is the intercept, b is the slope, and x is the concentration in μg/mL
