Department of Food Science, Rutgers, The State University of New Jersey, 65 Dudley Road, New Brunswick, NJ 08901, USA.
Molecules. 2019 Oct 6;24(19):3592. doi: 10.3390/molecules24193592.
UV-curable inks, coatings, and adhesives are being increasingly used in food packaging systems. When exposed to UV energy, UV-photoinitiators (PI's) present in the formulations produce free radicals which catalyze polymerization of monomers and pre-polymers into resins. In addition to photopolymerization, other free radical reactions occur in these systems resulting in the formation of chemically varied photolytic decomposition products, many of which are low molecular weight chemical species with high migration potential. This research conducted model experiments in which 24 commonly used PI's were exposed to UV-energy at the typical upper limit of commercial UV-printing press conditions. UV-irradiated PI's were analyzed by gas chromatography-mass spectrometry (GC-MS) and electrospray-mass spectrometry (ESI-MS) in order to identify photolytic decomposition products. Subsequently, migration studies of 258 UV-cure food packaging samples were conducted using GC-MS; PI's and photolytic decomposition products were found in nearly all samples analyzed. One hundred-thirteen photolytic decomposition products were identified. Eighteen intact PI's and 21 photolytic decomposition products were observed as migrants from the 258 samples analyzed, and these were evaluated for frequency of occurrence and migratory concentration range. The most commonly observed PI's were 2-hydroxy-2-methylpropiophenone and benzophenone. The most commonly observed photolytic decomposition products were 2,4,6-trimethylbenzaldehyde and 1-phenyl-2-butanone. This compilation of PI photolytic decomposition data and associated migration data will aid industry in identifying and tracing non-intentionally added substances (NIAS) in food packaging materials.
紫外线固化油墨、涂料和胶粘剂在食品包装系统中的应用越来越广泛。当暴露于紫外线能量时，配方中存在的紫外线光引发剂 (PI) 会产生自由基，自由基催化单体和预聚物聚合形成树脂。除光聚合外，这些系统中还会发生其他自由基反应，导致形成化学变化的光解分解产物，其中许多是具有高迁移潜力的低分子量化学物质。本研究进行了模型实验，将 24 种常用的 PI 暴露于商业 UV 印刷机条件的典型上限的紫外线能量下。通过气相色谱-质谱联用仪 (GC-MS) 和电喷雾质谱联用仪 (ESI-MS) 分析 UV 照射后的 PI，以鉴定光解分解产物。随后，使用 GC-MS 对 258 个紫外线固化食品包装样品进行了迁移研究；在几乎所有分析的样品中都发现了 PI 和光解分解产物。鉴定出 113 种光解分解产物。从分析的 258 个样品中观察到 18 种完整的 PI 和 21 种光解分解产物作为迁移物，并对其出现频率和迁移浓度范围进行了评估。最常见的 PI 是 2-羟基-2-甲基丙基苯酮和二苯甲酮。最常见的光解分解产物是 2,4,6-三甲基苯甲醛和 1-苯基-2-丁酮。本研究中 PI 光解分解数据和相关迁移数据的汇编将有助于行业识别和追踪食品包装材料中的非故意添加物质 (NIAS)。
