Research On The Test Methods Of Hazardous Organic Compounds In Plastic Food Packaging Products

Plastic products are widely used in beverages, edible oil, milk and other food packaging. As a direct contact with food packaging materials, the most important thing is to sound contents. However, a large number of studies show that the plasticizers di(2-ethylhexyl) adipate (DEHA) and bis(2-ethlhexyl) phthalate (DEHP) are harmful to human of their carcinogenic, teratogenic and mutagenic. In addition, feeding bottles and polycarbonate (PC) buckets which produced by recycled CD-ROM and recycled PC respectively, and the harmful substances would be potential harmful to human health.By taking food packaging products such polyvinyl chloride (PVC), polyethylene glycol terephthalate (PET), PC as the subjects, the test methods of the three typical hazardous organic compounds (including DEHA, DEHP and PAHs) which exsit in these plastic food packaging products were researched in this paper. According to the different swelling characteristic of high molecular polymer, fast sample pretreatment technique and test methods were established through choosing different extract solvents for PVC, PET and PC.The samples which extracted by i-propanol, n-hexane, isooctane, dichloromethane and the mixtures of dichloromethane with the others, analysed by GC-FID, and a method for the fast determination of DEHA in PVC products was established. The experimental results in a optimal proportion is in volume ratio of 5∶1 between n-hexane and dichloromethane. The recovery range is 85.3% ~ 94.6%, and the RSD is 1.02% ~ 2.74%. Compare with other sample pretreatment methods, the developed method is simple, fast and effective.Moreover, by Fenton reaction, the hydroxyl free radical was produced and then attacked sodium phthalate, finally the fluorescent sodium hydroxyl phthalate was formed. Base on the fluorescent sodium hydroxyl phthalate, the DEHP in PVC products can be determined indirectly by fluorimetry, and the linear range of calibration curve of DEHP concentration and fluorescence intensity is 4.28×10-2~2.14mg·ml-1, the correlation coefficient is 0.9954.The simulation experiments were carried out to test PAHs in plastic food packaging, in which PET and PC were blended with recycled plastics as the simulants. PAHs in the simulants and products can be extracted by n-hexane/monochlorobenzene or n-hexane /acetone, and determined by GC-FID. When the simulants blended with recycled plastics, the test results show that there are more complex injurants in the samples, such as naphthalene, acenaphthylene, acenaphthene and other hazardous organic compounds.