Photoinitiators are widely used to cure ink on packaging materials used in food applications such as carton boards and can contaminate the food by migrating into the food. In this contribution, a fast and reliable confirmation method for the determination of photoinitiators in dry foodstuffs is described: benzophenone (BP), 4,4′‐bis(diethylamino)benzophenone (DEAB), 2‐chloro‐9H‐thioxanthen‐9‐one (CTX), 1‐chloro‐4‐ropoxy‐9H‐thioxanthen‐9‐one (CPTX), 2,2‐dimethoxy‐ 2‐phenyl acetophenone (DMPA), 4‐(dimethylamino)benzophenone (DMBP), 2‐ethylanthraquinone (EA), 2‐ethylhexyl‐4‐dimethylaminobenzoate (EDB), ethyl‐4‐dimethylaminobenzoate (EDMAB), 4‐hydroxybenzophenone (4‐HBP), 1‐hydroxycyclohexyl phenyl ketone (HCPK), 2‐hydroxy‐4‐methoxybenzophenone (HMBP), 2‐hydroxy‐4′‐(2‐hydroxyethoxy)‐2‐methylpropiophenone (HMMP), 2‐isopropyl‐9H‐thioxanthen‐9‐one (ITX), 4‐methylbenzophenone (MBP), 4,4′‐bis(dimethylamino)benzophenone (MK) and 4‐phenylbenzophenone (PBZ). Dry foodstuffs were extracted using acetonitrile, followed by the addition of inorganic salts to precipitate fatty residues. After filtration, the extract was analysed using ultra‐performance liquid chromatography in combination with tandem mass spectrometry (UPLC‐MS/MS). Quantification was carried out using benzophenone‐d10 (BP‐d10) as internal standard. The presented method was successfully validated in‐house. Afterwards, the procedure was applied in a marketing study, investigating 97 dry foodstuffs purchased on the Belgian market. In 89% of the samples, at least one photoinitiator was detected. The photoinitiators BP, EDMA and DMPA were most frequently found, while some photoinitiators (CPTX, DEAB, DMBP, HCPK, HMBP and MK) were never detected. Copyright © 2016 John Wiley & Sons, Ltd.

Photoinitiators are widely used to cure ink on packaging materials used in food applications such as cardboards for the packaging of dry foods. Conventional migration testing for long-term storage at ambient temperature with Tenax(®) was applied to paperboard for the following photoinitiators: benzophenone (BP), 4,4'-bis(diethylamino)benzophenone (DEAB), 2-chloro-9H-thioxanthen-9-one (CTX), 1-chloro-4-propoxy-9H-thioxanthen-9-one (CPTX), 4-(dimethylamino)benzophenone (DMBP), 2-ethylanthraquinone (EA), 2-ethylhexyl-4-dimethylaminobenzoate (EDB), ethyl-4-dimethylaminobenzoate (EDMAB), 4-hydroxybenzophenone (4-HBP), 2-hydroxy-4-methoxybenzophenone (HMBP), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (HMMP), 2-isopropyl-9H-thioxanthen-9-one (ITX), 4-methylbenzophenone (MBP) and Michler's ketone (MK). Test conditions (10 days at 60°C) were according to Regulation (EU) No. 10/2011 and showed different migration patterns for the different photoinitiators. The results were compared with the migration in cereals after a storage of 6 months at room temperature. The simulation with Tenax at 60°C overestimated actual migration in cereals up to a maximum of 92%. In addition, the effect of a lower contact temperature and the impact of the Tenax pore size were investigated. Analogous simulation performed with rice instead of Tenax resulted in insufficiently low migration rates, showing Tenax is a much stronger adsorbent than rice and cereals.

Photo-initiators are widely used to cure ink on packaging materials used in food applications such as plastic films or cartonboards. In migration studies, food simulants are very often used to simulate food, like Tenax(®), which is the simulant for dry foodstuffs. In this paper a fast and reliable confirmation method for the determination of the following photo-initiators in Tenax(®) is described: benzophenone (BP), 4,4'-bis(diethylamino)benzophenone (DEAB), 2-chloro-9H-thioxanthen-9-one (CTX), 1-chloro-4-propoxy-9H-thioxanthen-9-one (CPTX), 2,4-diethyl-9H-thioxanthen-9-one (DETX), 2,2-dimethoxy-2-phenyl acetophenone (DMPA), 4-(dimethylamino)benzophenone (DMBP), 2-ethylanthraquinone (EA), ethyl-4-dimethylaminobenzoate (EDMAB), 1-hydroxylcyclohexyl phenyl ketone (HCPK), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (HMMP), 2-isopropyl-9H-thioxanthen-9-one (ITX), 4-methylbenzophenone (MBP), Michler's ketone (MK), and 4-phenylbenzophenone (PBZ). After the migration study was completed, the simulant Tenax(®) was extracted using acetonitrile, followed by analysis on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Quantification was carried out using benzophenone-d10 (BP-d10) as internal standard. The presented method is validated in terms of matrix effect, specificity, linearity, recovery, precision and sensitivity, showing the method can detect all photo-initiators at very low concentrations (LOD < 0.125 µg g(-1) for all substances). Finally, the procedure was applied to real samples, proving the capabilities of the presented method.

Contaminants in food packaging are a challenge of our time since the packaging material itself has been found to represent a source of food contamination through the migration of substances from it. Before first use, packaging materials destined for the packaging of dry foods can be evaluated by performing migration experiments with the simulant for dry foods, Tenax®. This simulant is commercially available as a powder that is more difficult to handle during the migration experiments. This paper reports the development of a Tenax film. The film can be applied to the cardboard surface to conduct the migration test. After the migration is completed, the film can be easily extracted to determine the concentration of the contaminants in the film. Finally, the performance of the Tenax film was compared with the conventional Tenax powder for the evaluation of 15 model migrants.