| Composite plastic packaging materials have small mass,good mechanical property-es,stable chemical properties, and fine optical performance characteristics. The materia-lls are widely used for foodstuff packaging. Adding plasticizer of Di-2-ethylhexyl phthalate (DEHP) to the packaging material can improve material's performance in the production process. When packaging materials are in contact with food, the DEHP will move into the food, and will potentially be harmful to human health. Due to the strong lipotropism characteristics of DEHP, using the packaging material to pack fatty food increases the harmful migration of DEHP into the fatty food. Therefore, studying the methods for testing for DEHP is extremely important and is necessary. It is especially important to be able to test for DEHP in fatty food and research how it moves into fatty food.In this paper, three methods used to extract DEHP from fatty food simulation have been analyzed. The three extracting methods include ultrasound extraction, florisil solid phase extraction, and liquid phase micro-extraction. The ways to improve the testing and extracting conditions by GC analysis will also be included. The experimental data analysis indicates:1.The optimum way to extract DEHP is by using a specific type of solvent. In case of ultrasonic method, the procedure requires 20ml acetonitrile (50% acetone),65℃and 50min. In florisil solid phase extraction, the sample solution was poured through the column extractor of 6ml/min, and then 30ml n-hexane was used to elution the column extractor. The most important relationship is between the rotational speed of stir and extract efficiency. For the third extraction method, the liquid phase micro-extraction, 2μl acetonitrile(50% acetone)was used to form the single drop at temperature of 30℃. The magnetic stirrer's rotational speed was 600rpm and was extracted for 20min. The significant factors were the volume of drop and stir speed. 2. In analyzing the linearity range, percent recovery, and precision, the best linear relationship occurred when the mass concentration of DEHP is between 50μg/l and 1000μg/1. On the other hand, the percent recovery of three extract methods was 90% and the precision was below 10%. Overall, the precision of florisil solid phase extraction was the best.In addition, this paper includes the different effects of layers on the movement of DEHP in the NY15/RCPP65 composite packaging materials, the effects of temperature, the process of sterilization and the effect of simulation volume on the movement of DEHP. The experimental results indicated:1. In enough soak migration experiments, at the same migratory time, the rate of movement of DEHP in composite packaging materials does not add up equally for different layers', the result indicated that there is migration partition between the different packaging material.2. The migration of DEHP in NY15/RCPP65 composite packaging materials was affected by migration temperature,sterilize process and simulation volume, but migration temperature was the most influential factor. At a low temperature, the sterilization process and simulation volume had greater influenced on the movement of DEHP than that of high temperature. At a high temperature, the movement of DEHP measured greater than at the low temperature per unit time.3. In the migration experiment, at 121℃, there was some oily material on the packet surface after 280h migration time, it proved that the movement of DEHP in the plastic packaging material and fatty food simulation occurred on both sides of the packet. When DEHP moved into the fatty food in the simulation, DEHP moved into packaging material from both sides at the same time.
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