Occurrence of 2,2,4-trimethyl–1,3-pentanediol monoisobutyrate (Texanol®) in foods packed in polystyrene and polypropylene cups

Abstract

After simultaneous distillation–extraction (SDE) of foods packed in polystyrene (n = 77) and polypropylene cups (n = 42) from 61 different suppliers, coupled capillary gas chromatography–mass spectrometric (HRGC–MS) analyses indicated the presence of diastereomers of 2,2,4-trimethyl–1,3-pentanediol monoisobutyrate (TMPD-MIB; Texanol®), a known coalescent of paints and printing inks. The contaminant was found in 55 and 50% of the polystyrene and polypropylene packed samples, respectively. Amounts ranged 1.2–64.5 µg kg⁻¹ in polystyrene cups (average 25.1 µg kg⁻¹) and 0.9–45.7 µg kg⁻¹ in polypropylene cups (average 10.8 µg kg⁻¹). The origin of Texanol® in the printed plastic cups was demonstrated by separate HRGC–MS analysis, showing amounts in the higher µg kg⁻¹ range. In addition, the presence of two pairs of enantiomers, both found to be racemic by enantioselective multi-dimensional gas chromatography–mass spectrometry (enantio-MDGC–MS), excluded it being of natural origin. The detection limit of overall procedure (DLOP) and the reliable quantification limit (RQL) were 0.2 and 0.9 µg kg⁻¹, respectively. As the diester, 2,2,4-trimethyl–1,3-pentanediol diisobutyrate (TXIB), is on the EU list of regulated substances (restricted to single-use gloves only) with a migration limit of 5 mg kg⁻¹ in food and is metabolised rapidly by hydrolysis, the observed migration of the monoester Texanol® at the µg kg⁻¹ level poses no risk of adverse effects.

Keywords:

• contamination
• migration
• polypropylene
• polystyrene
• 2,2,4-trimethyl–1,3-pentanediol monoisobutyrate
• TMPD-MIB
• Texanol®