Use of atmospheric pressure solids analysis probe time-of-flight mass spectrometry to screen for plasticisers in gaskets used in contact with foods.

RATIONALE: Plasticisers are used in the PVC gaskets of metal closures on glass jars and bottles used for foods and beverages. They may migrate and so contaminate the packed foodstuff. The plasticisers are present in a high proportion and are often a complex mixture of substances leading to time-consuming analytical methodologies. This work describes a rapid screening method to identify the plasticisers used. METHODS: Analysis was carried out by direct sampling of the gaskets using atmospheric pressure solids analysis probe (ASAP) with time-of-flight (TOF) mass spectrometry (MS) using a SYNAPT G2 HDMS system. The accurate mass information collected was then compared to a user-prepared database of plasticisers to aid identification. RESULTS: The rapid identification approach was shown to be successful for 24 gasket samples previously analysed by alternative more lengthy gas chromatographic (GC) methods. Quantification by dissolution followed by standard addition was also demonstrated to be reliable. CONCLUSIONS: The ASAP-TOFMS method is a useful technique for rapidly screening gaskets for the presence of plasticisers. It can be used to identify specific gaskets deserving of further quantitative analysis by chromatographic methods, saving time and money by avoiding unnecessary analyses. Copyright © 2015 John Wiley & Sons, Ltd.

Exposure to phthalic acid, phthalate diesters and phthalate monoesters from foodstuffs: UK total diet study results.

Phthalates are ubiquitous in the environment and thus exposure to these compounds can occur in various forms. Foods are one source of such exposure. There are only a limited number of studies that describe the levels of phthalates (diesters, monoesters and phthalic acid) in foods and assess the exposure from this source. In this study the levels of selected phthalate diesters, phthalate monoesters and phthalic acid in total diet study (TDS) samples are determined and the resulting exposure estimated. The methodology for the determination of phthalic acid and nine phthalate monoesters (mono-isopropyl phthalate, mono-n-butyl phthalate, mono-isobutyl phthalate, mono-benzyl phthalate, mono-cyclohexyl phthalate, mono-n-pentyl phthalate, mono-(2-ethylhexyl) phthalate, mono-n-octyl phthalate and mono-isononyl phthalate) in foods is described. In this method phthalate monoesters and phthalic acid are extracted from the foodstuffs with a mixture of acidified acetonitrile and dichloromethane. The method uses isotope-labelled phthalic acid and phthalate monoester internal standards and is appropriate for quantitative determination in the concentration range of 5-100 µg kg⁻¹. The method was validated in-house and its broad applicability demonstrated by the analysis of high-fat, high-carbohydrate and high-protein foodstuffs as well as combinations of all three major food constituents. The methodology used for 15 major phthalate diesters has been reported elsewhere. Phthalic acid was the most prevalent phthalate, being detected in 17 food groups. The highest concentration measured was di-(2-ethylhexyl) phthalate in fish (789 µg kg⁻¹). Low levels of mono-n-butyl phthalate and mono-(2-ethylhexyl) phthalate were detected in several of the TDS animal-based food groups and the highest concentrations measured corresponded with the most abundant diesters (di-n-butyl phthalate and di-(2-ethylhexyl) phthalate). The UK Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) considered the levels found and concluded that they did not indicate a risk to human health from dietary exposure alone.

Determination of phthalate diesters in foods.

Methodology for the determination of 15 phthalate diesters (dimethyl phthalate, diethyl phthalate, diisopropyl phthalate, diallyl phthalate, diisobutyl phthalate, di-n-butyl phthalate, di-n-pentyl phthalate, di-n-hexyl phthalate, benzyl butyl phthalate, dicyclohexyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate, and di-n-decyl phthalate) is described. The method was validated in-house and its broad applicability demonstrated by the analysis of high-fat, high-carbohydrate and high-protein foodstuffs as well as combinations of all three major food constituents. Following on from the analysis of the 20 UK Total Diet Study samples, 261 foodstuffs were purchased and tested for their phthalate levels. Phthalate diesters were confirmed to be present in 77 samples. Di-(2-ethylhexyl) phthalate was the most frequently detected (66 samples), although the highest levels found were for the isomeric mixture diisononyl phthalate. Additional studies confirmed that, for some foodstuffs, packaging materials did contribute to the phthalate diester concentration in the foodstuff and one example is presented.