Migration From Food Packaging Paper To The Air Using Xylene As Orgnic Surrogates

During the process of pulp and paper making, different types of additives have been added to improve the performance of packaging materials. The studies have found that the packaging materials were a source of contamination through the migration of substances from the packaging into food. The purpose of this work is to study the migration of the potentially hazardous substances from food paper-packaging to the air.Xylene as the standard surrogate of volatile organic compounds is studied in this paper. Five paper samples are chosen. The study contents include two parts. Firstly, the thermodynamics studies, including determinations and analysis of the partition coefficients of vapor-gas phase equilibrium (VSE) of xylene, and drawing the adsorption isotherms. Secondly, the migration study of xylene from paper-packaging to the air, as kinetics studies.For this purpose, it was necessary to develop a new method of analysis for fiber materials. This study reports on an indirect headspace gas chromatographic method (HS-GC) for the study of VSE. The present method can accurately measure a wide range of VSE partitioning coefficients of solutes. The time sequence of the multiple extractions in multiple headspace gas chromatographic (MHE-GC) technique to automate the study of process kinetics that involves volatile species was developed in this paper.A number of main conclusions can be drawn from the paper:1. The indirect HS-GC was developed to study the partition coefficients of VSE. The method is rapid and automated. Therefore, the present method can accurately measure the partition coefficients of VSE.2. High partition coefficient values were generally measured for xylene indicating significant sorption levels into paper-packaging. The partition coefficients of the xylene decrease with increasing temperature, indicating that the use of paper and board samples as food-packaging materials at high temperatures is more risky.3. The adsorption isotherms of the studied compounds onto paper samples are of Longmuir type.4. Real migration curves of xylene from paper-packaging to the air was gained at different temperature. The migration process can be regard as first-order reaction, the energy of activation is 15.8kJ/mol, the reaction speed constant are 0.0019, 0.0013, 0.0045, at 40℃,70℃,100℃, respectively.