Research On The Determination Of Antioxidants In Food And Drug Packaging Materials

The packaging materials (especially for the type of polymer, such as PP and PE), which directly contact with the food and drug, usually becomes fade, harden, and loss gloss or transparency after been oxidized in its lifetime. In order to control and put off the oxidation action, the antioxidants are added during the processing. Unfortunately, these antioxidants could migrate from packaging material into food and drug stuffs, furthermore, migrate into human body with the food and drug. So, they must be determined for safety and regulatory reasons. A comprehensive analytical method was developed for measuring the6most commonly used antioxidants-BHA, BHT, TBHQ, Irganox1010, Irganox1076and Irgafosl68. The main results are as follow:1. The extraction solvent and extraction way were studied in the experiment. The scanning electron microscope (SEM) was used to observe the surface of the polymer immersed in different extraction solvent. The result showed that cyclohexane has a much stronger swelling melting power than isopropanol. Moreover, dissolving experiment indicated that isopropanol has a better solubility for the antioxidants than cyclohexane. Therefore, it can be concluded that cyclohexane acts as the role of the swelling agent, isopropanol acts as the other. The single-factor variance analysis was used to optimize the MAE conditions. The optimum conditions of MAE was obtained at a an extraction temperature of80℃, with a heating time of15min, using a solvent mixture of cyclohexane-isopropanol (25:75,v/v). Comparison with two other commonly used extraction techniques-heating under reflux (RF) and ultra-sonic extraction (UAE), the MAE has the advantages of highest recoveries, shortest extraction time (15min) and lowest RSD (less than10%).2. A high performance liquid chromatography (HPLC-SPD) method for determination of4antioxidants-BHT, Irganox1010, Irganox1076and Irgafosl68in food and drug packaging materials has been explored. Several parameters of HPLC were optimized, such as the UV detection wavelength and the chromatographic condition. The extracts were separated by an Inertsil(?)C18column. Two gradient elusion programs were compared. The methanol-water gradient elusion was found to be more advantageous than the acetonitrile-water gradient elusion. Under the optimal conditions, the calibration curves showed a good linearity (r2>0.9990) in the concentration ranged from1.0-100.0mg/L for4target compounds. Recoveries of4analyses at three spiked levels ranged from76.4%to98.9%, with relative standard deviations (RSDs) less than10%. The detection limits of the method ranged from0.044to0.095mg/L. This method is sensitive and simple, and suitable for the rapid determination of the antioxidants added in food and drug packaging materials.3. Gas chromatography method was established for determination of4low molecular antioxidants-BHA, BHT and TBHQ. Choose of the column was discussed. The programmed heating was optimized. The extracts were separated by an Rtx(?)-5column and quantified by external standard method with a FID detector. The calibration curves showed a good linearity (r2>0.998) in the concentration ranged from5.0-100.0mg/L for the3target compounds. Recoveries of the3analyses at three spiked levels ranged from81.0%～95.2%, with relative standard deviations (RSDs) less than10%. The detection limits of the method ranged from0.16～0.41mg/L. This method is sensitive and simple, and is suitable for the rapid determination of the antioxidants added in food and drug packaging materials.