Study On The Migration Characteristics Of Phthalic Acid Esters In PVDC Used As Food Contact Materials In Food

Plastic is the most commonly used food contact material in daily life, and some phthalate plasticizers (PAEs) are added during its processing. These PAEs will migrate to food under certain conditions, leading to food contamination and endangering human health. Poly vinylidene chloride (PVDC), as a new type of food contact material, is currently less studied. In this paper,PVDC materials are used as materials to analyze the migration characteristics of PAEs under different conditions by gas chromatography-mass spectrometry (GC-MS).The main research contents of this paper include: (1) To establish the detection method of 18 kinds of PAEs in food contact PVDC materials; (2) To investigate the effects of different time,temperature, food simulation liquid,aging temperature and aging time on the migration of PAEs in PVDC materials. The results include three aspects:(1) A method for simultaneous determination of 18 kinds of PAEs in food contact PVDC was established by GC-MS using external standard method. The retention time, qualitative and quantitative determination of 18 kinds of PAEs were determined. Experiments show that the method has the advantages of good precision,high accuracy and low LOD, and is suiTab. for qualitative and quantitative detection of PAEs in food contact materials.(2) Distilled water, 4% acetic acid, 65% ethanol and n-hexane were used as food simulants in the experiment, and the migration experiments were carried out at the temperature of 40 ℃, 20 ℃ and 4 ℃. The results show that PVDC material have migrated diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), dicyclohexyl phthalate (DCHP) and phthalic acid di (2-ethyl) hexyl ester (DEHP), the migration characteristics as follows: in the same food simulants, migration quantity of PAEs increase with the increases of migration time; in the same temperature,the trend of migration quantity of PAEs in different food simulants is n-hexane > 65% ethanol >distilled water≈ 4% acetic acid; in the same food simulants, migration quantity of PAEs increase with the increase of migration temperature.(3) The aging temperature is 60℃, 80 ℃ . The aging time is 72h, 144h, 216h and 288h. PVDC samples were subjected to thermal oxidative aging. The aging samples were subjected to migration experiments and GC-MS respectively. The effect of aging conditions on the migration of PAHs was studied by using DHCP as representative. The experimental results show that the migration characteristics of PAEs with migration time, migration temperature, food simulants in different aged samples are same as that in original samples; under the same experimental conditions,the migration quantity of PAEs in aged samples decreases with the increases of aging time; under the same experimental conditions, the migration quantity of PAEs in aged sample decreases with the increases of aging temperature in distilled water, 4%acetic acid and 65% ethanol; in n-hexane, the relationship between the migration quantity of PAEs and the aging temperature is not obvious.This study satisfies the research demand for the migration of PAEs in PVDC materials in domestic market, and provides data support for the establishment of its service life model, which is of great significance to the safe use of PVDC materials.