Chemia Analityczna, cilt.3, sa.50, ss.593-603, 2005 (SCI-Expanded)
A derivative spectrophotometric method with zero-crossing
has been described for the simultaneous determination of ternary dye mixtures:
Carmoisine, Tartrazine, and Beetroot Red (E-122, E-102, and E-162), and Sunset
Yellow, Tartrazine, and Beetroot Red (E-110, E-102, and E-162) ) in powdered
drinks. The procedure involves extraction of the dyes from a powdered drink
with distilled water, filtration, appropriate dilution, recording of the first-
and second derivative UV spectra, and the measurement of absorbance values at
zero-crossing wavelengths. Sensitivity and reproducibility of the method were
determined using the standard mixtures. The proposed method was applied to the
determination of the above dyes in commercially available powdered drink.
RP-HPLC has been also applied as the reference method. Statistical evaluation
of the results confirmed good agreement between both methods. However,
derivative spectrophotometry has the advantage of being simple, fast, inexpensive
and easy to perform.