Paper packaging materials are widely used in food packaging. However, it is difficult to extract trace chloropropanol from food packaging paper, so there is a lack of research on the leaching of chloropropanol from paper materials. Therefore, it is of positive significance to explore the leaching rule of chloropropanol in paper pulp for the safety of paper packaging materials, to reduce the risk of food packaging to food safety and to provide a theoretical basis for the formulation of safety standards for paper packaging materials. In order to study the content of chloropropanol in paper packaging paper more accurately, a response surface methodology was used to study the relationship between the amount of chloropropanol leaching and pulp concentration, leaching temperature and leaching time, as well as the interaction of each factor. The results showed that time, temperature and pulp concentration were the main factors affecting the leaching amount of chloropropanol from paper packaging materials. There were significant (p > 0.05) interactions between the time and pulp concentration, as well as temperature and pulp concentration. The leaching efficiency of chloropropanol was higher at a lower pulp concentration, and the leaching amount of chloropropanol was higher at a lower temperature. The temperature more significantly affected the leaching of chloropropanol in a low-concentration system than in a high-concentration system. Relevant studies have shown that the selection of solvent has an important effect on the extraction rate of target compounds. Therefore, in this experiment, different polar organic solvents (methanol, ethanol, formaldehyde solution) were added into the soaking solution to change the leaching amount of chloropropanol. The results showed that adding a certain amount of formaldehyde solution can obviously increase the leaching amount of chloropropanol in pulp.
Keywords: chloropropanol; extraction; formaldehyde solution; paper material; response surface analysis.