Abstract:

A method was developed for the simultaneous determination of Sudan Red Ⅰ, Ⅱ, Ⅲ and Ⅳ in foods by high performance liquid chromatography (HPLC) with a clean-up procedure by gel column. Sample was extracted from foods with ethanol. The extract was cleaned up with a Bio-Beads SX3 gel column (200 mm×10 mm i.d.) and eluted with cyclohexane-ethyl acetate (1∶1, v/v). The analysis was performed on a Symmetry Shield RP18 column (250 mm×4.6 mm i.d., 5 μm) with 100% methanol as the mobile phase at a flow rate of 1.5 mL/min, detection at 478 nm and confirmation by diode-array spectra. All of the four compounds demonstrated good linear relationship (r>0.999) in the range of 0.1-10.0 mg/L. The limits of detection (LOD) were from 7 to 14 μg/kg. The average recoveries for all four dyes (spiked at the levels of 0.25 and 2.5 mg/kg) in chili sauce and sausage ranged from 80.7% to 96.3%, and the relative standard deviations were from 2.4% to 5.9%. The method is sensitive, reliable and can be applied for the analysis of four Sudan Red dyes in foods.

Key words: food , high performance liquid chromatography, Sudan Red dyes, gel column