717019.fig.003a
(a)
717019.fig.003b
(b)
717019.fig.003c
(c)
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).