Abstract:

A high-performance liquid chromatographic (HPLC) method was developed for the determination of acid orange 7 in foods. Samples were extracted with n-hexane saturated acetonitrile, and the extract was then extracted twice with acetonitrile saturated n-hexane for the removal of oily pigments and other impurities. The resulting lower phase was subjected to HPLC analysis using Agilent ZORBAX SB-C18 column set at 40 ℃ followed by detection with a diode array detector (DAD) detector at 484 nm. Binary linear gradients were achieved using mobile phase A: acetonitrile and mobile phase B: 0.3% acetic acid aqueous solution at a flow rate of 1.0 mL/min. The calibration curve for determination of acid orange 7 by the method exhibited good linearity over the concentration from 0.01 to 1.0 mg/L with a correlation coefficient of 0.9997 and the limit of detection (LOD) of the method was 0.05 mg/kg. Mean recoveries of 6 replicates for acid orange 7 in 6 different matrix samples spiked at the levels of 0.05, 0.1 mg/kg and 0.2 mg/kg ranged between 74.9% and 100%, with a relative standard deviation (RSD) range of 1.41% to 8.64%. The method proved good in intra-laboratory accuracy and precision.

Key words: food, acid orange 7, high-performance liquid chromatography, diode array detector, determination