Four Derivative Spectrophotometric Methods for the Simultaneous Determination of Carmoisine and Ponceau 4R in Drinks and Comparison with High Performance Liquid Chromatography

Figure 1

Zero-order spectra (a) of 10 μg mL⁻¹ Carmoisine, 10 μg mL⁻¹ Ponceau 4R, and their binary mixture; first derivative spectra (b) of colorants (Carmoisine(—): 2–10 μg mL⁻¹; Ponceau 4R (- -): 2–10 μg mL⁻¹).

(a)

(b)