An accurate method based on the use of reversed-phase high performance liquid chromatography coupled with diode-array detection was devised for the determination of five synthetic food colorants added to alcoholic beverages with natural colors. A C18 stationary phase was used and the mobile phase contained methanol and 40 mM ammonium acetate buffer solution. The synthetic food colorants were detected at their corresponding individual characteristic maxima of absorbance wavelength. Successful separation was achieved within 11 min for all the analytes using an optimized gradient elution, column temperature, buffer concentration and flow rate. Accurate sample quantification was feasible using matrix-matched calibration curves. The method was successfully validated by determination of linearity ranges, the limits of quantification and detection, precision and recovery for all colorants tested. The proposed and validated method was used to analyze some alcoholic beverage samples, consisting of eight red wines, six coolers, four aromatized spirits, five bitters, three cocktails and four liquors from different Chinese manufacturers. The results showed the bitters and red wines did not have synthetic colorants, but colorants were found in all the samples of other kinds of alcoholic beverages. No analyzed sample exceeded the limit established by Chinese legislation.
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