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

Table 4

Assay results for the determination of Carmoisine and Ponceau 4R in soft drinks using the proposed methods and the reference HPLC method (NMKL 130).

Methods	Analyte	Selected wavelengths (nm)	Assay results mean ± SD* (𝑡calculated; 𝐹calculated)**
			Soft drink I (µg 100 mL^−1)	Soft drink II (µg 100 mL^−1)
DSM	C	^1D331	9.30±0.22(0.68;1.45)	6.28±0.29(0.61;1.44)
	P	^1D517	2.20±0.11(1.18;1.18)	1.39±0.13(0.40;1.79)
RDM	C	^1D323	9.26±0.23(0.37;1.45)	6.36±0.21(1.28;1.20)
	P	^1D344	2.35±0.11(0.44;1.25)	1.43±0.13(0.13;1.69)
DDM	C	^1D366	9.31±0.24(0.73;1.69)	6.41±0.24(1.53;1.64)
	P	^1D451	2.49±0.17(1.89;3.02)	1.44±0.16(0.23;2.68)
CM	C	^1D472/^1D569	9.30±0.26(0.63;1.88)	6.36±0.28(1.07;2.11)
	P	^1D470/^1D554	2.30±0.16(0.23;2.56)	1.43±0.19(0.10;3.68)
HPLC	C	520	9.21±0.18	6.20±0.19
	P	512	2.32±0.10	1.42±0.10

∗Results obtained are the average of five experiments for each method; SD: standard deviation.
**The corresponding theoretical value for 𝑡 and 𝐹 at 𝑃: 0.05 (𝑡_theoretical: 2.31; 𝐹_theoretical: 6.39).