Determination of polyadipates migrating from lid gaskets of glass jars. Hydrolysis to adipic acid and measurement by LC–MS/MS

Abstract

Polyadipate plasticizers can be present in the polyvinylchloride (PVC) gaskets used to seal the lids of glass jars. As the gaskets can come into direct contact with the foodstuffs inside the jar, the potential exists for polyadipate migration into the food. The procedure and performance characteristics of a test method for the analysis of polyadipates in food simulants (3% aqueous acetic acid and 10% aqueous ethanol) and the volatile test media used in substitute fat tests (isooctane and 95% aqueous ethanol) are described. The PVC gaskets were exposed to the food simulants or their substitutes under standard test conditions. Studies were initially carried out using direct measurement of the polyadipate oligomers by liquid chromatography with time-of-flight mass spectrometric detection (LC-TOF-MS) but this was not practical due to the number of peaks detected. Instead, the migrating polyadipates were hydrolysed to adipic acid and measured by liquid chromatography with tandem mass spectrometric detection (LC-MS/MS). The amount of polyadipate that this measurement of adipic acid represents was then calculated. Method performance was assessed by analysis of gaskets from two types of jar lids by single-laboratory validation. Linearity, sensitivity, repeatability, intermediate reproducibility and recovery were determined to be suitable for checking compliance with the 30 mg/kg specific migration limits for polyesters of 1,2-propane diol and/or 1,3- and/or 1,4-butanediol and/or polypropylene-glycol with adipic acid, which may be end-capped with acetic acid or fatty acids C(12)-C(18) or n-octanol and/or n-decanol. The method was found to be much quicker than previous methods involving extraction, clean-up, hydrolysis, esterification, derivatisation and GC measurement, consequently saving time and money.

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

“…Polyadipates were also detected in three other samples by ASAP but were not identified by GC. It can be noted that detection of polyadipates by the ASAP method does provide an indication of which polyadipate standards were used in the formulation of the gasket, whereas the other methods break down the polyadipates and so there is no indication of the type or composition of the polyadipate used.…”

Multiresidual LC–MS analysis of plasticizers used in PVC gaskets of lids and assessment of their migration into food sauces

“…In this case, an easy sample preparation procedure entailing an extraction step with dichloromethane without any further clean‐up was proved . This work surely relaunched the research for an alternative LC–MS approach to the plasticizers determination with respect to the traditional gas chromatography mass spectrometry (GC/MS) one …”

“…[12] This work surely relaunched the research for an alternative LC-MS approach to the plasticizers determination with respect to the traditional gas chromatography mass spectrometry (GC/MS) one. [13,14] Effectively, ten years later, for instance, the LC-MS/MS, preceded by QuEChERS and SPE preparative steps, has been used to analyze simultaneously 23 phthalates achieving good results in a variety of foods including oil, grain, meat, biscuit, wine, beverage, milk-based products, distilled liquor and canned products. [15] Then, in the last couple of years, also high-resolution mass spectrometry was exploited for determining plastic additives in packaging.…”

A computer‐aided methodology to design safe food packaging and related systems

“…Most of the past and recent crises have thus involved materials, which were considered either “safe” or “inert” before a proof of leaching and a contamination of the product in contact has been demonstrated. Without being exhaustive, it includes contamination of aquaculture systems by di‐ n ‐octylphthalate, contamination of noodles by mineral oil from paperboard, contamination of milk by bisphenol A from polycarbonate baby bottles, contamination of butter by polybrominated diphenyl esters from wrapping paper, contamination by melamine from tableware or can coating, contamination of dairy products and dry food by photoinitiators of printing ink, contamination of fatty or aqueous‐alcoholic food by phthalate plasticizers or adipate plasticizers, contamination of food by primary aromatic amines, and so forth.…”