Non-targeted screening for contaminants derived from food contact water-borne coatings and risk assessment based on (Q)SAR matrix

Abstract

Because of great knowledge gaps between toxicological data and chemical constituents for substances involved, water-borne coating paper and board have emerged as a sort of particular concern for the safety of consumers. Herein, we describe a step-by-step method including extraction, gas chromatography-mass spectrometry (GC-MS) fractionation, tentative identification of related substances and risk assessment of chosen tentatively identified substances based on (Quantitative) Structure-Activity Relationships ((Q)SARs) matrix. Three water-borne coating samples possessing different compositions were investigated. Polyacrylates were first determined as the possible compositions of coating samples based on Fourier transform infrared spectrophotometer (FTIR) and differential scanning calorimetry (DSC) analysis. 7 out of 23 elemental compositions determined by inductively coupled plasma emission spectrometry (ICP-OES) were demonstrated for peaks over a specific migration limit evidencing the likely heavy metal contamination from water-borne coatings. Of 359 tentatively identified substances, 85 and 38 substances were assigned to Hazard Ⅳ and Risk Ⅳ, respectively, disclosing the particular concern for consumer safety, which may originate from decomposition products and impurities from industrial processing. Overall, understanding the identity of contaminant will allow it easier to find the possible source, and to study which part of the water-borne coating paper-producing process that could be amended to mitigate the risk.