2-Hydroxy-1-naphthaldehyde-P-hydroxybenzoichydrazone: A New Chromogenic Reagent for the Determination of Thorium(IV) and Uranium(VI)

Figure 3

Second order derivative spectra of (a) [Th(IV)-HNAHBH] and (b) [U(VI)-HNAHBH]. Th(IV) (μg mL⁻¹): 0.464; 0.928; 1.392: U(VI) (μg mL⁻¹): 0.952; 1.428; 1.904.