Simultaneous Determination of 8 Kinds of Synthetic Colorants in Complex Food Matrix by HPLC

HPLC combined with solid phase extraction was applied to the simultaneous determination of 8 kinds of synthetic colorants, including tartrazine, sunset yellow, amaranth, carmine, allura red, azorubin, erythrosine and brilliant blue in complex food matrix. The sample was extracted ultrasonically with a mixture of ethanol-acetonitrile-methanol-ammonia (3+3+3+1) for 3 times. The extract was cleaned up by using a ProElut PWA-2 solid phase extraction column. The purified solution was seperated on an Agilent Eclipse XDB-C₁₈ column, with a mixture of acetonitrile and 0.02 mol·L^-1 ammonium acetate solution as the mobile phase for gradient elution. The analytes were detected by using diode array detector at the wavelength of 254 nm. Linear relationships were found between the peak areas and the mass concentrations of the 8 kinds of synthetic colorants in the range of 1.0-50.0 mg·L^-1, with detection limits in the range of 0.25-0.80 μg·kg^-1. Recovery rates obtained by standard addition method were in the range of 84.6%-99.0% and RSDs (n=6) were in the range of 1.4%-2.5%.