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

Figure 2

First derivative ratio spectra of Carmoisine (a) and Ponceau 4R (b) for different concentrations (Carmoisine (6 μg mL⁻¹ Ponceau 4R was used as a divisor); a: 2 μg mL⁻¹, b: 4 μg mL⁻¹, c: 6 μg mL⁻¹, d: 8 μg mL⁻¹, e: 10 μg mL⁻¹; Ponceau 4R (6 μg mL⁻¹ Carmoisine was used as a divisor); f: 2 μg mL⁻¹, g: 4 μg mL⁻¹, h: 6 μg mL⁻¹, i: 8 μg mL⁻¹, j: 10 μg mL⁻¹).

(a)

(b)