Migration of 17 Photoinitiators from Printing Inks and Cardboard into Packaged Food – Results of a Belgian Market Survey

Abstract

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.

Use of Tenax® films to demonstrate the migration of chemical contaminants from cardboard into dry food

“…In 2016, Van Den Houwe et al performed migration experiments for the migration of several photo-initiators from cardboard in cereals after a contact of 6 months at room temperature (Van Den Houwe et al, 2016). About 5.4% BP migrated in cereals after a six months contact between the cereals and the cardboard at room temperature (Van Den Houwe et al, 2016). The percentage of migration of BP in the Tenax ® films was 26.1% using a smooth cardboard and 14.1% using a more rough cardboard to establish the migration contact for 10 days at 60°C.…”

Comparative study of ink photoinitiators in food packages using gas chromatography with vacuum ultraviolet detection and gas chromatography with mass spectrometry

“…Various articles have been published in the last ten years, presenting different analytical approaches to detect PIs in food (especially packaged milk [10][11][12][13][14][15][16][17][18][19], tea [10], fruit juice [13,19,20], wine [13], yoghurt, and sausage [19] or cereals, bread, rice, and pasta [21]), and in food plastic and paper packaging [13,19,20,[22][23][24][25]. Due to the complex matrix of both food or food packages, pretreatment methods such as conventional liquid-liquid extraction [12,16,17,[19][20][21][22][23]25], solid phase extraction [10,[13][14][15]24], or solid-phase microextraction [11,18] are necessary to extract and purify PIs. The main techniques utilized for the PI analysis are traditional GC-MS [11][12][13][18][19][20]…”

“…Due to the complex matrix of both food or food packages, pretreatment methods such as conventional liquid-liquid extraction [12,16,17,[19][20][21][22][23]25], solid phase extraction [10,[13][14][15]24], or solid-phase microextraction [11,18] are necessary to extract and purify PIs. The main techniques utilized for the PI analysis are traditional GC-MS [11][12][13][18][19][20]22,24], LC-MS [12,13], GC-MS/MS [10,14], UHPLC-MS/MS [15,21] or HPLC-diode array detection [16,17,20,23]. Another described technique, SFC coupled to photo diode array detection and MS/MS [25], has proven particularly useful and was successfully applied to the determination of this group of compounds during migration from polyethylene food packaging.…”

Synthesis and characteristics of photopolymerized benzophenone

“…A small quantity of photoinitiators (PIs) is the most vital components in the UV curable systems by generating reactive species, free radicals, or ions, which initiate the polymerization of acrylate monomers by UV light irradiation . Unfortunately, the very small quantity of PIs, which is consumed in the polymerization process, usually is prone to migrate out of the crosslinked polymer networks over time, resulting in some potential health risk especially in the field of food packaging materials . In 2005, the contamination discovered in baby milk products of Swiss‐based food giant Nestle, which has a tendency to migrate from the packaging into packaged foodstuffs, has caused a huge stir in Europe.…”

“…5,6 Unfortunately, the very small quantity of PIs, which is consumed in the polymerization process, usually is prone to migrate out of the crosslinked polymer networks over time, resulting in some potential health risk especially in the field of food packaging materials. 7 In 2005, the contamination discovered in baby milk products of Swiss-based food giant Nestle, 8 which has a tendency to migrate from the packaging into packaged foodstuffs, has caused a huge stir in Europe. After that, European Commission strictly limited the migration quantity of substances for food packaging.…”