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.

Recently, migration of mineral oil components from food contact materials into various foods has been reported. The analysis of mineral oil in food is complicated since it consists of mineral oil saturated hydrocarbons (MOSH) comprising a complex mixture of linear, branched and cyclic compounds and variable amounts of mineral oil aromatic hydrocarbons (MOAH), mainly alkylated. Both MOSH and MOAH form 'humps' of unresolved peaks in the chromatograms with the same range of volatility. Since these two fractions have a different toxicological relevance, it is important to quantify them separately. Occurrence data on mineral oil are available only for a limited number of food groups and only from few countries. In Belgium, data on the contamination of food by mineral oil are lacking. In this contribution, an in-house validated online combination of liquid chromatography with gas chromatography (LC-GC) with flame ionisation detection (FID) was used for the quantification of MOSH and MOAH. Totally, 217 packed food samples were selected using a well-defined sampling strategy that targeted food categories which are highly consumed and categories suspected to contain mineral oil. For 19 samples, the method was not applicable. For the 198 remaining samples, MOSH was detected in 142 samples with concentrations up to 84.82 mg kg. For the MOAH fraction, there are 175 samples with a concentration below the limits of quantification (LOQ), while 23 samples had a higher concentration ranging from 0.6 to 2.24 mg kg. Finally, these results were compared with the action thresholds as proposed by the Scientific Committee (SciCom) of the Belgian Food Safety Agency (FAVV-AFSCA). Only one sample exceeded the threshold for MOSH, while the threshold for MOAH was exceeded in 23 samples. For the samples exceeding the action threshold, further investigation is needed to identify the contamination source.

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.

Packaging materials are found to represent a source of contamination through the migration of substances from the packaging into the foodstuff. As a response to an increasing number of food‐safety issues, research on the migration of chemicals from packaging materials into foodstuffs is being conducted. Moreover, packaging materials are tested for the migration of chemicals through migration experiments, using food simulants. EU Regulation N°10/2011 on plastic materials and articles intended to come into contact with food specifies the use of the adsorbent poly(2,6‐diphenylphenylene oxide) or Tenax® as a simulant for dry foodstuffs. Already in 2010, Tenax® migration profiles in the temperature range between −18 and 40°C were modelled for some compounds. Since then, numerous studies have been reported on the migration and migration kinetics of a series of contaminants such as alkylbenzenes, antioxidants, fatty acid esters, isothiazolinone biocides, photo‐initiators, mineral oil and phthalates in Tenax®. In some of these studies, the migration to Tenax® has been compared to real foodstuffs or alternative simulants. In this contribution, the performance of Tenax® as food simulant for dry foodstuffs will be discussed, thereby comparing its performance with real foodstuffs and other potential adsorbents that can be used as simulant such as Porapak.