HPLC Determination of Synthetic Colorants in Meat Food

A method for the determination of 8 kinds of synthetic colorants, including tartrazine, amaranth, ponceau 4R, sunset yellow, allura red, red 2G, carmoisine and erythrosine in meat food by HPLC with diode array detector (DAD) was proposed. The sample was extracted with a mixed solution of 4 mol·L-1 urea solution and methanol (1+1), and the extract was purified and enriched successively by matrix dispersive SPE and the self-made polyamide SPE columns. The eluate obtained were separated on XDB-C18 column (250 mm×4.6 mm, 5 μm), using a mixture of 0.01 mol·L-1 NaOAc solution and acetonitrile-methanol (1+1) in different mixing ratios as mobile phase in the gradient elution. Quantitative analysis was performed by determining at the absorption maximum of the synthetic colorants, and qualitative analysis was performed with their specific absorption spectra. Eight synthetic colorants were completely separated within 25 min. Linear relationships between values of peak areas and mass concentration of the 8 synthetic colorants were kept in the same range of 0.05-50.0 mg·L-1, with detection limits (3S/N) in the range of 0.02-0.1 mg·kg-1. The proposed method was used in the analysis of meat food, i.e. sausage, crab rod and cooked shrimp; and values of recovery found by standard addition method were in range of 86.3%-98.8% with RSD′s (n=6) in the range of 1.2%-4.4%.