Redox-Reaction Based Spectrophotometric Assay of Isoniazid in Pharmaceuticals

Figure 3

(a) Effect of volumes of F-C reagent (1 : 1) on the reaction product with INH (6 μg mL⁻¹) in Na₂CO₃ solution for method A. (b) Effect of 20% Na₂CO₃ on color formation (6 μg mL⁻¹ INH) for method A. (c) Reaction time and stability of colored species for method A (6 μg mL⁻¹ INH).

(a)

(b)

(c)