Combination of Multidimensional Instrumental Analysis and the Ames Test for the Toxicological Evaluation of Mineral Oil Aromatic Hydrocarbons

Abstract

Mineral oil aromatic hydrocarbons (MOAHs) include mutagenic and carcinogenic substances and are considered a potential health risk. Current methods address the total MOAH content but cannot address the actual toxicological hazard of individual components. This work presents a combined methodology closing those gaps: high-performance liquid chromatography (HPLC) coupled to gas chromatography with flame ionization detection was used to determine the MOAH content. To characterize present substance classes, comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry was applied. Preparative HPLC separated MOAHs into subgroups, which were tested with a miniaturized Ames test evaluating DNA reactivity of isolated fractions. Combining these methods allowed a correlation between present subgroups and DNA reactivity. The developed approach was applied to a mineral oil and distinguished between not DNA-reactive mono-and diaromatics and DNA-reactive triand polyaromatics, providing a proof of concept. Hereinafter, it will be applied to diverse sample matrices including mineral oils, food, and food contact materials.

Update of the risk assessment of mineral oil hydrocarbons in food

“…Although no association between composition of the MOAH containing mineral oils and result in the Comet assay is apparent from the study, the findings do not contradict the conclusions by EFSA CONTAM Panel (2012) that genotoxicity is associated with some 3 or more ring MOAH. Hochegger et al (2022) used preparative LC to separate different MOSH or MOAH fractions of a mineral oil (MOLTOX reference oil no.1) and tested DMSO extracts of the fractions for mutagenicity in an Ames test employing S. Typhimurium strain TA98 in the presence of metabolic activation (S9). The total MOSH fraction was negative in this assay while the total MOAH fraction was positive.…”

“…Hochegger et al. ( 2022 ) used preparative LC to separate different MOSH or MOAH fractions of a mineral oil (MOLTOX reference oil no.1) and tested DMSO extracts of the fractions for mutagenicity in an Ames test employing S. Typhimurium strain TA98 in the presence of metabolic activation (S9). The total MOSH fraction was negative in this assay while the total MOAH fraction was positive.…”

Safety Assessment of Recycled Plastics from Post-Consumer Waste with a Combination of a Miniaturized Ames Test and Chromatographic Analysis

“…Very high-fold inductions were detected for multiple samples (see Figure 3, Supplementary Table S1), which were, e.g., significantly higher than signals from an equally tested DNA-reactive aromatic hydrocarbon fraction of a mineral oil [33]. Such high activity is usually only achieved for very active standard substances such as DNA-reactive positive controls.…”

One-dimensional and comprehensive two-dimensional gas chromatographic approaches for the characterization of post-consumer recycled plastic materials

“…They must originate from the recycling input materials, where they could be present because of the intended use of PP as, e.g., a fuel canister, or because of unintended use (e.g., refilling of containers by consumers) or as another form of contamination due to their ubiquitous presence. The typical MOAH fraction is considered to be potentially mutagenic and carcinogenic, because of the possible presence of 3–7 ring polycyclic aromatic hydrocarbons (PAHs) [ 28 – 30 ]. If MOAH is detected in a food sample, more comprehensive analytical techniques shall be used for a detailed identification of substances present.…”