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

Table 2

Statistical parameters of the simultaneous determination of Carmoisine and Ponceau 4R by DSM, RDM, and DDM.

Methods	Analyte	Selected wavelength (nm)	Concentration range (µg mL^−1)	Regression equations^a	Correlation coefficient; (𝑟)	Detection limit; (µg mL^−1)	Quantification limit; (µg mL^−1)
DSM	C	^1D331	2–10	1.56⋅10^−4𝐶+1.90⋅10^−5	0.9995	0.086	0.286
	P	^1D517	2–10	2.32⋅10^−4𝐶−3.20⋅10^−5	0.9996	0.091	0.304
RDM	C	^1D323	2–10	4.13⋅10^−3𝐶−3.23⋅10^−4	0.9994	0.079	0.263
	P	^1D344	2–10	1.95⋅10^−3𝐶−3.43⋅10^−3	0.9996	0.082	0.273
DDM	C	^1D366	2–10	3.25⋅10^−4𝐶+1.27⋅10^−4	0.9996	0.071	0.236
	P	^1D451	2–10	4.39⋅10^−4𝐶−1.56⋅10^−4	0.9998	0.081	0.270

aFive separate determinations were performed and mean was calculated.
𝐶^∗: the concentration of the analyte (µg mL⁻¹).