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).