Migration Analysis of Compounds from Food Packaging Material
|Keywords||Migration Model Diffusion coefficient Partition Coefficient Migration assay Food Packaging PET|
With the rapid development of materials science , polymer materials to different forms more and more widely used in food packaging . However, due to the polymer characteristics of the material itself and its modified processing , resulting in the formation of low molecular weight compounds , giving food safety hidden trouble , but also endanger people's health . To solve this problem , before the selection of materials , we must analyze the migration of the polymer material of low molecular weight compounds , to consider the impact of the migration process of the packaging materials used . In this paper, migration mathematical model and the impact on the migration of the important parameters of the model - the diffusion and distribution coefficients , while taking advantage of the existing experimental conditions , determination of PET bottle grade material compound ( chlorobenzene and phenol) migration over time , and then The experimental data and the existing migration mathematical model analysis and comparison . This paper analyzes and compares the existing single and double migration model , and discussed the food solution to swell the constraints of the boundary layer and food viscous non-ideal factors on the impact of the migration process . Diffusion and distribution coefficients have a major impact on the migration model , semi-empirical formula of the diffusion coefficient and free volume formula , and the allocation coefficient of regular solution theory model and group contribution model . Experimental part , chlorobenzene and phenol as a PET bottle used on the market containing a trace amount , so this experiment the high concentration soaking method to enlarge the measured concentration of the compound . In order to ensure good analysis of the migration assay sensitivity needs , also called polymer matrix does not change the characteristics of this experiment, the concentration of 2000ppm as the target measured values . Were chosen in order to simulate the food environment of use of PET bottles , four n-hexane , 3% acetic acid , 15% ethanol and distilled water as the food simulant . Soaking a sample of the four solutions take a different time , with a gas chromatographic determination of chlorobenzene and the amount of migration of the phenol , using the internal standard method (internal standard for quantitative analysis pentadecane ) . After analysis, the experimental data in line with the the Fick dynamics .