Development and validation of a multi-analyte GC-MS method for the determination of 84 substances from plastic food contact materials

Abstract

Chemical substances shall not migrate from food contact materials (FCM) at levels that are potentially harmful for the consumers. Each of the current analytical methods applied to verify the migration of substances from FCM covers only one or few substances. There is a very limited number of publications on the development of analytical methods allowing the simultaneous determination of several classes of FCM substances, and almost none of them reported methods entirely dedicated to the ones in the positive list of Commission Regulation (EU) No. 10/2011 for plastic FCMs. Therefore, a simple, sensitive and reliable multi-analyte method was developed for the analysis of FCM substances in food simulants. It employs an optimised liquid-liquid extraction with dichloromethane as extraction solvent in the presence of 10% m/v NaCl, followed by quantitative analysis with gas chromatography coupled to mass spectrometry (GC-MS). A combination of total ion chromatograms (TICs) and extracted ion chromatograms (EICs) was used. The optimisation and validation of the method have been carried out according to current international guidelines. Adequate sensitivity was demonstrated in the selected concentration ranges for most of the analytes, with limits of quantification (LOQs) at least three times lower than the legislative limit, when existing. The results showed that the method is sufficiently accurate for the majority of substances, with recoveries between 70 and 115% and relative standard deviations (RSDs) smaller than 20% at three concentration levels. The method was applied to the analysis of some FCM multilayers. The method allows, for the first time, the simultaneous quantification of 84 FCM substances in two of the official food simulants (A and C) at levels of a few ng g −1 . Graphical abstract Electronic supplementary material The online version of this article (10.1007/s00216-020-02758-7) contains supplementary material, which is available to authorized users.

Polystyrene Biodegradation by Tenebrio molitor Larvae: Identification of Generated Substances Using a GC-MS Untargeted Screening Method

“…The applied analytical method was considered fit-for-purpose for this study, taking into consideration its existing thresholds and limitations [18,20]. The selection of the extraction solvent was based on previous studies, where it was shown that DCM is good extracting solvent for a majority of the FCM substances, PS monomers and oligomers, and NIAS [1,15]. Moreover, although a polar column (Innowax) has been used, the peak quality for the fatty acids was low, with their identification being based on NIST library and injection of standards.…”

“…For the extraction, a method previously reported by our group [15] was slightly modified. Briefly, a lyophilized sample of 0.5 g of the collected insects' larvae was placed in a glass tube and extracted twice, with 1.0 mL of dichloromethane (DCM).…”

“…The selection of the extraction solvent was based on previous studies, where it was shown that DCM is a good extracting solvent for a majority of the FCM substances, NIAS and PS monomers and oligomers [1,15]. The results indicate that there are several substances existing within the insects' biomass, apart from the residual monomers, oligomers or plastic additives.…”

“…Identified substances were further assessed and confirmed based on their respective and representative m/z and a similarity index higher than 80%. Furthermore, for PS monomers and oligomers existing spectral data were used [1,15]. Finally, the preliminary identification of substances was confirmed by injecting respective analytical standards for every single suspect ( Table 1).…”

“…Analysis of styrene, α-methyl styrene and related oligomers have been performed in the context of multianalyte GC-MS methods [15]. Dedicated targeted GC-MS methods for those substances have also been reported [1].…”