Development and application of a non-targeted extraction method for the analysis of migrating compounds from plastic baby bottles by GC-MS

Abstract

In 2011, the European Union prohibited the production of polycarbonate (PC) baby bottles due to the toxic effects of the PC monomer bisphenol-A. Therefore, baby bottles made of alternative materials, e.g. polypropylene (PP) or polyethersulphone (PES), are currently marketed. The principal aim of the study was the identification of major compounds migrating from baby bottles using a liquid-liquid extraction followed by GC/MS analysis. A 50% EtOH in water solution was selected as a simulant for milk. After sterilisation of the bottle, three migration experiments were performed during 2 h at 70°C. A non-targeted liquid-liquid extraction with ethyl acetate-n-hexane (1:1) was performed on the simulant samples. Identification of migrants from 24 baby bottles was done using commercially available WILEY and NIST mass spectra libraries. Differences in the migrating compounds and their intensities were observed between the different types of plastics, but also between the same polymer from a different producer. Differences in the migration patterns were perceived as well between the sterilisation and the migrations and within the different migrations. Silicone, Tritan™ and PP exhibited a wide variety of migrating compounds, whereas PES and polyamide (PA) showed a lower amount of migrants, though sometimes in relatively large concentrations (azacyclotridecan-2-one up to 250 µg kg⁻¹). Alkanes (especially in PP bottles), phthalates (dibutylphthalate in one PP bottle (±40 µg kg⁻¹) and one silicone bottle (±25 µg kg⁻¹); diisobutylphthalate in one PP (±10 µg kg⁻¹), silicone (up to ±80 µg kg⁻¹); and Tritan™ bottle (±30 µg kg⁻¹)), antioxidants (Irgafos 168, degradation products of Irganox 1010 and Irganox 1076), etc. were detected for PP, silicone and Tritan™ bottles. Although the concentrations were relatively low, some compounds not authorised by European Union Regulation No. 10/2011, such as 2,4-di-tert-butylphenol (10-100 µg kg⁻¹) or 2-butoxyethyl acetate (about 300 µg kg⁻¹) were detected. Migrating chemicals were identified as confirmed (using a standard) or as tentative (further confirmation required).

Identification of substances migrating from plastic baby bottles using a combination of low‐resolution and high‐resolution mass spectrometric analysers coupled to gas and liquid chromatography

“…Ten PP baby bottles and one PA baby bottle from the Belgian market, consisting the majority of the market share, were selected for the application of the developed methodology. The use of simulants is prescribed in the EU Regulation 10/2011 to mimic the migration testing towards real foods, leading to the selection of simulant D1 [water : EtOH (50 : 50)] as a simulant for milk .…”

“…After sterilisation of the bottles during 10 min with boiling water, three consecutive migrations for 2 h at 70 °C were performed with the water–EtOH simulant. Afterwards, a non‐targeted liquid–liquid extraction with ethyl acetate : n‐hexane (1 : 1) was performed on the simulant samples as previously described . The obtained organic extracts were then further concentrated to ± 75 µl under a gentle N 2 stream for analysis by GC or evaporated until dryness and dissolved in 75 µl of MeOH for LC injection.…”

“…(A). The analytical strategy to perform a non‐target analysis with GC‐MS techniques started from the results obtained in our previous work . In a first screening based on GC‐(EI)MS data using commercially available WILEY and NIST libraries with Agilent MSD Chemstation software, peaks with an area of at least 10% of the area of the IS were selected for identification.…”

“…The migration phenomenon in the alternative materials for baby bottles has been understudied up to now, and little is known about the possible migrants from these polymer alternatives. GC‐quadrupole‐MS with electron impact (EI) ionisation source has been used to investigate the presence of unknown compounds in food simulant that has been in contact with the alternative baby bottle plastics . The drawback of this approach is that a conclusive library match cannot always be obtained when comparing experimental and library EI spectra, as many migrating compounds can be new, unregulated or even non‐intentionally added substances, e.g.…”

“…To our knowledge, this is the first time that a combination of these techniques has been applied in a non‐targeted approach to elucidate unknown migrants from plastic baby bottles. While it was not the goal of this work to give a complete overview of all detected compounds in the tested baby bottles, some particular examples have been selected to demonstrate the potential of the applied methodology for the elucidation of unknown plastic migrants.…”