Determination of antioxidant residues in polymer food package using gas chromatography

A new method for the determination of antioxidants, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and tertiary butylhydroquinone (TBHQ) in plastic food package by gas chromatography-electron capture detection (ECD) was developed. The antioxidants were extracted by cyclohexane with ultrasonic extraction, separated by an HP-50 + chromatographic column (30 m x 0.53 mm x 1 microm) and quantified by external standard method with an ECD detector. The average recoveries of antioxidants were 88% -93%, 92% - 101% and 83% -97% for BHT, BHA and TBHQ, respectively, at the spiking levels of 3.00 - 10.0 mg/kg. The corresponding relative standard deviations (RSDs, n = 5) were 2.01% - 2.89%, 2.11% - 3.19% and 2.99% - 4.02%, respectively. The limits of detection (S/N = 3) were 0.5, 0.5 and 0.8 mg/kg for BHT, BHA and TBHQ, respectively. The proposed method has been applied to the analysis of 5 kinds of polymer food package. The results indicated that all the above antioxidants were found in the practical polymer food package samples. Plastic food package contained BHT and BHA with the concentrations varying from 6.3 to 7.8 mg/kg and rubber food package contained all the three antioxidants with the concentrations varying from 9.3 to 28.4 mg/kg. This method is accurate, sensitive, highly reproducible and suitable for the analysis of residual antioxidants in polymer food package.