Simultaneous determination of five synthetic antioxidants in edible vegetable oil by GC-MS

A simple, quick and nontoxic analytical method for the simultaneous determination of five synthetic antioxidants [t-butyl-4-hydroxyanisole (BHA), 2,6-di-t-butyl-hydroxytoluene (BHT), t-butyl hydroquinone (TBHQ), ethoxyquin (EQ) and 2,6-di-tert-butyl-4-hydroxymethyl-phenol (Ionox 100)] in edible vegetable oil has been developed. The analytes were extracted by ethanol, then separated and detected by GC-MS. Extraction conditions such as volume of ethanol required, mixing time and number of extractions were investigated and optimized by an orthogonal array experimental design. The five compounds behaved linearly in the 0.100 approximately 20.0 mg/L concentration range, and the limits of detection (LOD) for BHA, BHT, TBHQ, EQ and Ionox-100 were 1.00, 0.92, 11.5, 0.83 and 1.39 microg/L, respectively. The recoveries at the tested concentrations of 1.00, 20.0 and 100 mg/kg were 75.6 approximately 123%, with coefficients of variation<10.0%. The proposed procedure was successfully applied to the simultaneous analysis of the five antioxidants in soybean oil, tea oil, edible blended oil, rap oil, peanut oil, peanut blended oil and sesame oil samples purchased from local supermarkets.