Sadler G, Pierce D, Lawson A, Suvannunt D, Senthil V
National Center for Food Safety and Technology, Illinois Institute of Technology, Summit-Argo 60501-1933, USA.
Food Addit Contam. 1996 Nov-Dec;13(8):979-89. doi: 10.1080/02652039609374484.
The safety of recycled plastics for food contact use is largely dictated by the ability of post-consumer organic contaminants to absorb into recycled materials and later diffuse from containers made from recycled plastics into the food supply. Diffusion and solubility data for organic contaminants in poly(ethylene terephthalate) (PET) are scarce. An approach for determining permeability constants, diffusion coefficients and solubility constants of slowly migrating contaminants in PET is described. Compounds (neat or in admixture) were heat-sealed in packets made from thin (0.00127 cm) PET films. Packets were placed in containers with GC sampling closures. Headspace (volatile compounds) or an external liquid medium (non-volatile compounds) was analysed for emergence of the compound. Diffusion coefficients were determined from non-steady state diffusion equations, permeability constants were determined from steady state permeation, and solubility constants were calculated from diffusion and permeability values. Diffusion coefficients (25 degrees C) ranged from 10(-9) to < 10(-16) cm2/s. The diffusion coefficient of benzene increased dramatically with concentration. Compounds with high permeation increased the transport rate of slower permeating volatiles.
回收塑料用于食品接触用途的安全性很大程度上取决于消费后有机污染物吸收到回收材料中并随后从由回收塑料制成的容器扩散到食品供应中的能力。聚对苯二甲酸乙二酯（PET）中有机污染物的扩散和溶解度数据很少。本文描述了一种测定PET中缓慢迁移污染物的渗透常数、扩散系数和溶解度常数的方法。将化合物（纯品或混合物）热封在由薄（0.00127厘米）PET薄膜制成的小包中。将小包置于带有气相色谱采样封盖的容器中。分析顶空（挥发性化合物）或外部液体介质（非挥发性化合物）中化合物的出现情况。根据非稳态扩散方程确定扩散系数，根据稳态渗透确定渗透常数，并根据扩散和渗透值计算溶解度常数。扩散系数（25℃）范围为10^(-9)至<10^(-16)平方厘米/秒。苯的扩散系数随浓度急剧增加。高渗透性化合物提高了低渗透性挥发性物质的传输速率。
