| Chapter 1:The problems and advances of polyurethane adhesive and polypropylene packaging materials safety as well as the factors caused these problems were discussed; In addition, the regulations in china and abroad, as well as the advances in this field have been reviewed. Our own research and creative content were put forward based on these reviews.Chapter 2:The raw materials of synthetic polyurethane adhesive, including 2,4-Diisocyanato-1-methylbenzene, triacetin, o-Toluidine 4-Aminobiphenyl,2,6-Toluenediamine and 4-tert-Butylphenol, were determinated by gas chromatography-mass spectrometry. These raw materials were dissolved by dichloromethane, after ultrasonic extraction and centrifugation, then analyzed by GC-MS. Acquisition was performed in full scan mode for the optimization and in SIM mode for the quantification. The standard curves have a good linear relationship (R>0.9967) in the range of 0.05～5.00mg/L. When spiking at concentration of 0.10,0.20,0.40 mg kg-1 the recoveries were 74.0%～120.1% with RSD (n=6) in the range of 3.6%～6.1%. The detection limit were 0.1～8.0 μg L-1. The method complete the separation of 6 kinds of toxic substances within 17 minutes, and has been applied to determine 6 kinds of substances in synthetic polyurethane adhesive.Chapter 3:Determination of 18 harmful substances in polypropylene food packaging materials by gas chromatography-mass spectrometry has been studied. The analyzed substance included aromatic amine, antioxidants, initiator, spices and solvent residue. Packaging materials were ultrasonic extracted using ethyl acetate as solvent, then analyzed by GC-MS. Acquisition was performed in full scan mode for the optimization and in SIM mode for the quantification. For building the calibration curves, solutions of the compounds at different concentration levels were prepared in ethyl acetate and analyzed by GC-MS. The standard curves were linear in the range of 0.05～5.0mg L-1 and have a good linear relationship (R>0.9943). Spiked at concentration of 0.10,0.20,0.40 mg L"’,the recoveries were 74.9%-121.3% with RSD 1.4%-6.8%(n=6). The detection limit were in the range of 1.5～80.0μg L-1. The method completed the separation and detection of 18 substances within 20 minutes. Results are accurate and reproducible. The method is applied to determined the 18 substances in polypropylene packaging materials.Chapter 4:Determination of 6 kinds of chemical additives in polypropylene packaging materials including toluene, m-xylene, benzaldehyde, phenol, linalool and butylp-hydroxybenzoate by gas chromatography-mass spectrometry has been studied. The standard curves were linear in the range of 0.05～5.0 mg L-1 and had a good linear relationship (R≥0.9959). Spiked at concentration of 50,100,200μg L-1, the recoveries were 70.9%～132.6% with RSD 0.1%～8.4% (n=6). The limit of detection were in the range of 1.0～13.0 μg L-1. According to European Union directive (EU)NO.10/2011, the quantity of 6 substances migrate to fatty food simulant (isooctane) were studied under temperature of 40,70,100℃. The results indicated that the internal structure of polypropylene materials influenced the amount of migration. The amount of migration decreased with the increasing of the degree of crystallinity and activation energies. The smaller the molecular weight of chemical additives, the easier it is moved out from packaging materials.Chapter 5:The main innovation and significance of this study were summarized and the future works of this study were discussed. |
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