纸塑包装中PCBs的迁移模型及效果评价

多氯联苯化合物种类繁多,无法逐一进行冗长的迁移试验,迁移模型不仅可以简化迁移研究,而且概括性强,适用范围广。文章基于"有限包装-有限食品"模型,考虑纸层与塑料层间的扩散系数,忽略其间分配系数的差异,建立迁移预测模型。并以Brandsch模型估算扩散系数,以定义式粗算分配系数,并分析迁移试验值与模拟预测情况的差异。对比结果显示,试验值变化的整体趋势与模型预测结果相符。迁移量均随着时间的延长而增加,且平衡时的迁移量随着温度的升高而加大,大多预测值明显略高于试验值。

Migration model and evaluation of PCBs in paper and plastic packaging

Polychlorinated biphenyls compounds include so many kinds that it’s impossible for migration experiment.Migration model could simplify the study of migration,and has a broad application.Migration modeled based on the model of"limited packaging-limited food"by taking into account diffusion coefficients of paper and plastic and ignoring the discrepancy between their partition coefficients.Diffusion coefficients were estimated with Brandsch Model and partition coefficient was rough estimated with its definition expression.The difference of migration experiment value and simulation was analyzed by Maple.The results showed that the overall variation trend of the experiment value was in accord with the model prediction,that is to say,migration increased with the prolong of time and added with the raise of temperature.Most of predicted values were slightly higher than migration experiment values.