Ink photoinitiators determination in cartboard packagings and contained food by GC/MS and HPLC/MS/MS.

INTRODUCTION The alert for food contamination by photoinitiators, a class of molecules used in UV-cured inks for printing the surface of polycoupled carton used as container for liquid food, arose in Europe in November 2005, when the Italian authorities withdraw from the market thirty million liters of infants milk, because of contamination with the photoinitiator 2-isopropylthioxanthone (ITX). Regarding effects of ITX on human health, there are contradictory opinions; in fact, no fully convincing data on ITX genotoxicity have been published to date. Very recently, a paper reported that ITX can affect the mobility/rigidity status of biological membranes by strong interactions with the cellular lipid bilayer. After that alert, factories producing cartonboard stated that no more ITX was used in packagings. MATERIALS AND METHODS In the present research, we developed and applied to market food samples a multiresidue method for the simultaneous detection and quantification of five of the most commonly used photoinitiators and co-initiators, namely ITX, 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB), Benzophenone, 1-hydroxycyclohexyl-1-phenyl ketone (IRGACURE 184), and ethyl-4-dimethylaminobenzoate (EDAB). Those contaminants were analyzed using gas chromatography–mass spectrometry (GC/MS) and liquid chromatography–mass spectrometry (LC/MS) techniques, both on the cartonboard packagings and contained liquid food; the method was applied to milk, fruit juices, and wine, previously purified by solid-phase extraction (SPE). RESULTS AND DISCUSSION Benzophenone was found in all forty analyzed food samples in a concentration range of 5–217 μg l−1. EHDAB was found in eleven beverages in a concentration range of 0.13–0.8 μg l−1, while ITX was found in three samples in a range 0.2–0.24 μg l−1. The proposed methods showed to be robust and reliable for the determination of the five analyzed contaminants in food.