Study On Material Identification And Safety Analysis Of Food Polymer Packaging

In recent years,the issue of food safety has attracted people's great attention,and food packaging materials are closely related to food safety.The regeneration and utilization of plastics and the residue of toxic substances in food packaging materials are the important factors that threaten the safety of food.Therefore,it is of great practical significance to carry out the research on the material identification,residual harmful components and their migration of food packaging.In this paper,the commonly used food packaging materials made from polyethylene(PE),polypropylene(PP)and polyethylene terephthalate(PET)were investigated,which were chosen from the commercial and sampling samples.Firstly,Fourier transform infrared spectroscopy(FTIR)and differential scanning calorimetry(DSC)were used to analyze the material as preliminary screening procedure.Then the content of acetaldehyde,phthalic acid ester plasticizers(PAEs),fluorescent whitening agent and heavy metal were examined,in which gas chromatography(GC),gas chromato graph-mass spectrometer(GC-MS),high performance liquid chromato graphy(HPLC),(ICP-MS)were utilized.Finally,the migration of PAEs plasticizers from food packaging to food simulation solution was explored at a set of temperature and time and food simulation solution by use of GC-MS.Results demonstrated that the carbonyl(C=O)component was found in FTIR spectrometry of samples made of PE and PP.The composition and crystallinity of the samples were analyzed in detail according to their characteristics of FTIR and DSC curves.This provided references for the further analysis of harmful substances in food packaging materials.Results of GC,GC-MS,HPLC,ICP-MS show that,acetaldehyde was found in 21 PET samples.Samples containing acetaldehyde of 1-3 g/g accounted for 25%,and samples containing acetaldehyde of 3-6 g/g accounted for 18%,and containing acetaldehyde more than 6 g/g accounted for 57%.Furtherly,the linearity was good and the linear correlation coefficient>0.99900.Fluorescent whitening agent was detected in 2 PET samples in the screening procedure among 47 PP,PET and PE samples.The content of fluorescent whitening agent was reached 566.946 mg/kg and 946.402 mg/kg,respectively.The migration of Pb and Sb in 21 PP samples were less than 1 mg/L.The content of PAEs plasticizers in food packaging materials was quantitatively screened by GC-MS technique.Furtherly,the migration of DIBP?DBP and DEHP to food simulation solution was investigated in detail.It revealed that the migration of plasticizers increased with the ambient tempeture and time.The migration quantity growth can be divided into three stages,first increased rapidly,then grew slowly,until it reached an equilibrium state.It indicated that the thermal motion of macromolecules is accelerated at high temperature,and the doped plasticizers in polymer matrix will diffuse to the surface of the sample.And in a certain temperature range,with the increase of temperatrre,the time to reach equilibrium is shortened.