717019.fig.002a
(a)
717019.fig.002b
(b)
Figure 2: (a) Absorption spectra of A: reaction product of INH (6 μg mL−1) with F-C reagent in Na2CO3 solution and B: blank. (b) Absorption spectra for method B, reaction product of INH (1.25 μg mL−1) with ferric chloride and ferricyanide solution (--) and blank (-Ο-).