Real-time and in situ monitoring of Irgacure 907 penetration into food plastic packaging through surface-enhanced Raman spectroscopy

Irgacure 907 is a highly efficient photoinitiator and is widely used in food packaging materials. Understanding the penetration behavior of photoinitiators in food plastic packaging is crucial for reducing the exposure of food to photoinitiators. However, a method for in situ monitoring of photoinitiator penetration is lacking. Therefore, a method for rapid, real-time, and in situ monitoring penetration behaviors of Irgacure 907 with common solvents for inks use into three types of plastics was developed based on surface-enhanced Raman spectroscopy. The results showed that the penetration ability of Irgacure 907 with different solvents on all three plastics was in the following order: acetone > acetonitrile > methanol > ethyl acetate > xylene. The effectiveness of polyethylene terephthalate and polypropylene in blocking Irgacure 907 penetration was higher than that of polyethylene. The findings of this study may provide guidance for safe application of photoinitiators on packages.

Automated summary

This study developed a method based on surface-enhanced Raman spectroscopy for rapid, real-time, and in situ monitoring of the penetration behavior of Irgacure 907 into three types of plastics with common solvents for inks use. The results revealed the penetration ability order of Irgacure 907 with different solvents and found that polyethylene terephthalate and polypropylene were more effective in blocking the penetration of Irgacure 907 compared to polyethylene.