Gas chromatography with mass spectrometry for the determination of phthalates preconcentrated by microextraction based on an ionic liquid

Abstract

A new procedure is proposed for the analysis of migration test solutions obtained from plastic bottles used in the packaging of edible oils. Ultrasound-assisted emulsification microextraction with ionic liquids was applied for the preconcentration of six phthalate esters: dimethylphthalate, diethylphthalate, di-n-butylphthalate, n-butylbenzylphthalate, di-2-ethylhexylphthalate, and di-n-octylphthalate. The enriched ionic liquid was directly analyzed by gas chromatography and mass spectrometry using direct insert microvial thermal desorption. The different factors affecting the microextraction efficiency, such as volume of the extracting phase (30 μL of the ionic liquid) and ultrasound application time (25 s), and the thermal desorption step, such as desorption temperature and time, and gas flow rate, were studied. Under the selected conditions, detection limits for the analytes were in the 0.012-0.18 μg/L range, while recovery assays provided values ranging from 80 to 112%. The use of butyl benzoate as internal standard increased the reproducibility of the analytical procedure. When the release of the six phthalate esters from the tested plastic bottles to liquid simulants was monitored using the optimized procedure, analyte concentrations of between 1.0 and 273 μg/L were detected.

Research progress on sample pretreatment methods for migrating substances from food contact materials

“…Cacho et al. [71] adopted emulsification LPME with ionic liquids ([C 6 MIm][NTf 2 ]) as extraction phase for the enrichment of PEs (dimethylphthalate, diethylphthalate, and di‐ n ‐octylphthalate) in the isooctane simulants from plastic bottles. A small amount of [C 6 MIm][NTf 2 ] could offer non‐polar environment to enrich trace PEs in isooctane.…”

Advanced Gas Chromatography in Food Analysis

“…All together makes to consider this technique an efficient and, cost-effective tool for large-scaled (i.e., industrial) processes. As a further illustration of this technique flexibility, it can be mentioned that USE has been successfully applied to as divergent applications as the extraction of natural antioxidant (i.e., hydroxychavicol, eugenol, isoeugenol and 4-allyl-1,2-diacetoxybenzen) from powdered Piper Betle leaves 57 , pesticides (i.e., organophosphorus pesticides and pyrethroids) from fruit peel 59 , or phthalates extracted from plastic bottles 60 , the later in times as short as 60 and 25 s, respetively. On the other hand, widely variable yields have been obtained for the USE of oils from natural sources, despite the general use of long extraction times 58 .…”

Bis(trifluoromethylsulfonyl)imide‐based frozen ionic liquid for the hollow‐fiber solid‐phase microextraction of dichlorodiphenyltrichloroethane and its main metabolites

“…Ionic liquids (ILs), resulting from the combination of organic cations and organic or inorganic anions, are defined as organic salts with melting points below 100°C [1]. Various ILs have been synthesized for obtaining unique properties such as negligible vapor pressure, good thermal stability, tunable viscosity and miscibility, and good extractability for various organic compounds and metal ions [2].…”