Simultaneous determination of the dyes yellow-5 and yellow-5 by ratio spectra derivative and measurement of the area of the ratios of spectra

In this work two spectrophotometric methods are described for the simultaneous determination of yellow-5 (C.I. 19140) and yellow-6 (C.I. 15985) in their mixtures: by first derivative of the ratio spectra and by measuring the area of the ratio spectra. The proposed procedure does not require any separation of the dyes prior to determination. Calibration graphs for both dyes were linear up to 32 mu g . mL(-1). The recoveries of Y5 and Y6 obtained in their mixtures (Y5:Y6 ratio were 0.5:7 and 7:0.5 (mim) respectively) were between 95 and 105% for both methods. The proposed methods were applied for the determination of Y5 and Y6 in different food products and satisfactory results were obtained.