Validation of methodology for simultaneous determination of synthetic dyes in alcoholic beverages by capillary electrophoresis.

In this work a method of analysis for synthetic dyes was developed using capillary electrophoresis in alcoholic beverages. The analyses were carried out with fused silica capillary, with 73 cm effective length, at 35 degrees C, buffer phosphate solution of 10 mmol/L with sodium dodecyl sulphate 10 mmol/L, pH 11, and +25 kV of voltage. For dye analyses, three wavelengths in the visible region were used for the qualitative and quantitative determination of the 11 synthetic dyes allowed in Brazil: 450, 525 and 625 nm for the yellow, red and blue dyes, respectively. The detection limits varied from 0.4 to 2.5 microg/mL and the quantification limits varied from 1.3 to 7.1 microg/mL. The average recovery was 92.6 and 104.0% at two levels of concentration. Repeatability for standards and spiked sample showed that the calculated values were greater than the observed values, demonstrating the precision of the method. The proposed and validated method was used to analyze some alcoholic beverage samples, consisting of 12 red wines, 9 coolers, 6 aromatized spirits, 7 bitters, 3 cocktails and 8 liquors from different Brazilian manufacturers. The results showed the coolers, bitters and red wines did not have synthetic dyes, but dyes were found in six of the eight analyzed liquor samples. In all the samples of cocktails and spirits, the presences of dyes were observed. No analyzed sample exceeded the limit established by Brazilian legislation (maximum 30 mg/100 mL).