Contamination of dry foods with trimethyldiphenylmethanes by migration from recycled paper and board packaging

Contamination of foods with trimethyldiphenylmethanes is reported and the origin is shown to be migration from food packaging materials of which the use of recycled carbonless copy paper was found to be the major source. This chemical is one of the solvents used in the carbonless copy paper and its presence in food and the environment has not been previously identified. In this paper we have pursued previous studies on diisopropylnaphthalenes and hydrogenated terphenyls contamination from packaging and now report the identification of this new food contaminant and present evidence of its source. Solid foods such as egg pasta, barley coffee and rice were analysed by GC/MS and a mean concentration of 18 mg/kg of trimethyldiphenylmethanes was found. Extracts from carbonless copy paper were analysed by proton NMR to characterize the trimethyldiphenylmethanes. Since trimethyldiphenylmethanes are found in solid food together with diisopropylnaphthalenes, and considering their similar chemical character, they may follow the same migration pathway as one another.