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

Table 3

Method validation for the simultaneous determination of Carmoisine and Ponceau 4R in laboratory prepared mixtures by the proposed methods.

Method		Accuracy (mean* ± RSD %)	Precision repeatability^a; (mean ± RSD %)	Intermediate precision^b; (mean ± RSD %)
DSM	C (^1D331)	100.8±0.87	100.1±0.96	99.91±1.02
	P (^1D517)	99.1±1.02	100.5±1.05	100.1±0.92
RDM	C (^1D323)	101.0±0.95	99.98±0.99	100.6±1.05
	P (^1D344)	98.25±0.93	99.83±0.98	100.4±0.96
DDM	C (^1D366)	100.4±1.07	98.95±1.05	99.92±0.98
	P (^1D451)	99.55±0.95	100.5±0.95	100.7±0.96
CM	C (^1D472/^1D569)	99.75±1.02	99.8±1.01	100.1±0.97
	P (^1D470/^1D554)	98.5±1.06	99.75±1.03	100.3±1.06

aThe intraday (𝑛=3), average of three concentrations (2, 6, and 10 µg mL⁻¹) for Carmoisine and Ponceau 4R repeated three times within the day.
^bThe interday (𝑛=3), average of three concentrations (2, 6, and 10 µg mL⁻¹) for Carmoisine and Ponceau 4R repeated three times in three successive days.
*The values of % recovery are an average of five replicates of each of five synthetic mixtures at different concentration ratios of C and P (2–10 µg mL⁻¹).
RSD %: relative standard deviation.