Ambient ionization-accurate mass spectrometry (AMI-AMS) for the identification of nonvisible set-off in food-contact materials

Comparison of LC-ESI, DART, and ASAP for the analysis of oligomers migration from biopolymer food packaging materials in food (simulants)

Biopolymers based on polylactic acid (PLA) and starch have numerous advantages, such as coming from renewable sources or being compostable, though they can have deficiencies in mechanical properties, and for this reason, polyester resins are occasionally added to them in order to improve their properties. In this work, migration from a PLA sample and from another starch-based biopolymer to three different food simulants was studied. Attention was focused on the determination of oligomers. The analysis was first performed by ultraperformance liquid chromatography quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF–MS), which allowed the identification of the oligomers present in migration. Then, the samples were analyzed by two ambient desorption/ionization techniques directly coupled to mass spectrometry (ADI), direct analysis in real-time coupled to standardized voltage and pressure (DART-MS) and atmospheric pressure solids analysis probe (ASAP-MS). These methodologies were able to detect simultaneously the main oligomers migrants and their adducts in a very rapid and effective way. Nineteen different polyester oligomers, fourteen linear and five cyclic, composed of different combinations of adipic acid [AA], propylene glycol [PG], dipropylene glycol [DPG], 2,2-dibutyl-1,3-propanediol [DBPG], or isobutanol [i-BuOH] were detected in migration samples from PLA. In migration samples from starch-based biopolymer, fourteen oligomers from poly(butylene adipate co-terephthalate) polyester (PBAT) were identified, twelve cyclic and two linear. The results from ADI techniques showed that they are a very promising alternative tool to assess the safety and legal compliance of food packaging materials.

Ambient mass spectrometry as a tool for a rapid and simultaneous determination of migrants coming from a bamboo-based biopolymer packaging

New bamboo-based biopolymers are used as food packaging materials, but it must be evaluated to ensure consumers safety. In this study, migration from a commercial bamboo-based biopolymer to ethanol 10% (v/v), acetic acid 3% (w/v) and ethanol 95% (v/v) was studied. The migrants were determined from three different perspectives. Volatile and semi-volatile compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). Twenty-five compounds were detected. In addition, a number of phytosterols were detected in ethanol 95%. Non-volatile compounds were identified and quantified by ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry (UPLC-Q/ToF). Twelve non-volatile compounds were detected in migration solutions, mainly melamine and its derivatives, coming from polymer resins present in the biopolymer. Melamine migration was higher than 50 mg/Kg in the third sequential migration test. Finally, the migration samples were analyzed by DART-SVP (direct analysis in real time coupled to standardized voltage and pressure). This methodology was able to detect simultaneously the main volatile and non-volatile migrants and their adducts in a very rapid and effective way and is shown as a promising tool to test the safety and legal compliance of food packaging materials.

Analytical Approaches for Analysis of Safety of Modern Food Packaging: A Review

Nowadays, food packaging is a crucial tool for preserving food quality and has become an inseparable part of our daily life. Strong consumer demand and market trends enforce more advanced and creative forms of food packaging. New packaging development requires safety evaluations that always implicate the application of complex analytical methods. The present work reviews the development and application of new analytical methods for detection of possible food contaminants from the packaging origin on the quality and safety of fresh food. Among food contaminants migrants, set-off migrants from printing inks, polymer degradation products, and aromatic volatile compounds can be found that may compromise the safety and organoleptic properties of food. The list of possible chemical migrants is very wide and includes antioxidants, antimicrobials, intentionally added substances (IAS), non-intentionally added substances (NIAS), monomers, oligomers, and nanoparticles. All this information collected prior to the analysis will influence the type of analyzing samples and molecules (analytes) and therefore the selection of a convenient analytical method. Different analytical strategies will be discussed, including techniques for direct polymer analysis.

Stabilities of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and their derivatives under controlled conditions analyzed using liquid chromatography coupled with tandem mass spectrometry

Bisphenol A diglycidyl ether (BADGE), bisphenol F diglycydyl ether (BFDGE), and their related compounds are widely used as precursors in production of epoxy resins. The high reactivity of these compounds makes the development of analytical methodologies that ensure appropriate metrological accuracy crucial. Consequently, we aimed to determine whether and to what extent the composition of the solution and storage conditions affect the stability of selected BADGE and BFDGE derivatives. The stabilities of these compounds were studied using liquid chromatography–tandem mass spectrometry with electrospray ionization (HPLC-ESI–MS/MS). The chromatographic method elaborated here has allowed for separation of the analytes in time shorter than 6 min, for both methanol and acetonitrile-based mobile phases. The obtained calibration curves for all analytes were linear in the range tested. The values of limit of detection (LODs) were in the range of 0.91–2.7 ng/mL, while values of limit of quantitation (LOQs) were in the range of 2.7–5.7 ng/mL. The chosen experimental conditions were compared in terms of the content of organic solvent in solution, storage temperature, and time. Our results show that the content of BADGE, BADGE·HCl, BFDGE, three-ring NOGE decreased with increasing water content (> 40% v/v). For BADGE and three-ring NOGE, significant changes in concentration were noted as early as 24 h after the test solutions had been prepared. In addition, a reduction in the storage temperature (4 to − 20 °C) reduced the rate of transformation of the monitored analytes. Our study will increase quality control in future research and may increase the reliability of the obtained results.

Ambient desorption/ionization mass spectrometry: evolution from rapid qualitative screening to accurate quantification tool

In this article, some recent trends and developments in ambient desorption/ionization mass spectrometry (ADI-MS) are reviewed, with a special focus on quantitative analyses with direct, open-air sampling. Accurate quantification with ADI-MS is still not routinely performed, but this aspect is considered of utmost importance for the advancement of the field. In fact, several research groups are devoted to the development of novel and optimized ADI-MS approaches. Some key trends include novel sample introduction strategies for improved reproducibility, tailored sample preparation protocols for removing the matrix and matrix effects, and multimode ionization sources. In addition, there is significant interest in quantitative mass spectrometry imaging. Graphical abstract Conceptual diagram of the ambient desorption/ionization mass spectrometry approach with different desorption/ionization probes.

Rapid Analysis of Bisphenol A and Its Analogues in Food Packaging Products by Paper Spray Ionization Mass Spectrometry

In this study, a paper spray ionization mass spectrometric (PS-MS) method was developed for the rapid in situ screening and simultaneous quantitative analysis of bisphenol A and its analogues, i.e., bisphenol S, bisphenol F, and bisphenol AF, in food packaging products. At the optimal PS-MS conditions, the calibration curves of bisphenols in the range of 1-100 μg/mL were linear. The correlation coefficients were higher than 0.998, and the LODs of the target compounds were 0.1-0.3 μg/mL. After a simple treatment by dichloromethane on the surface, the samples were analyzed by PS-MS in situ for rapid screening without a traditional sample pretreatment procedure, such as powdering, extraction, and enrichment steps. The analytical time of the PS-MS method was less than 1 min. In comparison with conventional HPLC-MS/MS, it was demonstrated that PS-MS was a more effective high-throughput screening and quantitative analysis method.

Applications of DART-MS for food quality and safety assurance in food supply chain

Direct analysis in real time (DART) represents a new generation of ion source which is used for rapid ionization of small molecules under ambient conditions. The combination of DART and various mass spectrometers allows analyzing multiple food samples with simple or no sample treatment, or in conjunction with prevailing protocolized sample preparation methods. Abundant applications by DART-MS have been reviewed in this paper. The DART-MS strategy applied to food supply chain (FSC), including production, processing, and storage and transportation, provides a comprehensive solution to various food components, contaminants, authenticity, and traceability. Additionally, typical applications available in food analysis by other ambient ionization mass spectrometers were summarized, and fundamentals mainly including mechanisms, devices, and parameters were discussed as well. © 2015 Wiley Periodicals, Inc. Mass Spec Rev. 36:161-187, 2017.

Progress in mass spectrometry for the analysis of set-off phenomena in plastic food packaging materials

In most cases, food packaging materials contain inks whose components can migrate to food by diffusion through the material as well as by set-off phenomena. In this work, different mass spectrometry approaches had been used in order to identify and confirm the presence of ink components in ethanol (95%) and Tenax(®) as food simulants. Three different sets of materials, manufactured with different printing technologies and with different structures, were analyzed. Sample analysis by ultra performance liquid chromatography mass spectrometry (UPLC-MS), using a quadrupole-time of flight (Q-TOF) as a mass analyser proved to be an excellent tool for identification purposes while ion mobility mass spectrometry (IM-MS) shown to be very useful for the confirmation of the candidates proposed. The results showed the presence of different non-volatile ink components in migration such as colorants (Solvent Red 49), plasticizers (dimethyl sebacate, tributyl o-acetyl citrate) or surfactants (SchercodineM, triethylene glycol caprilate). An oxidation product of an ink additive (triphenyl phosphine oxide) was also detected. In addition, a surface analysis technique, desorption electrospray mass spectrometry (DESI-MS), was used for analyzing the distribution of some ink components (tributyl o-acetyl citrate Schercodine L, phthalates) in the material. The detection of some of these compounds in the back-printed side confirmed the transference of this compound from the non-food to the food contact side. The results also showed that concentration of ink migrants decreased when an aluminum or polypropylene layer covered the ink. When aluminum was used, concentration of most of ink migrants decreased, and for 5 out of the 9 even disappeared.

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.

High-throughput differentiation of heparin from other glycosaminoglycans by pyrolysis mass spectrometry

Sensors with high chemical specificity and enhanced sample throughput are vital to screening food products and medical devices for chemical or biochemical contaminants that may pose a threat to public health. For example, the rapid detection of oversulfated chondroitin sulfate (OSCS) in heparin could prevent reoccurrence of heparin adulteration that caused hundreds of severe adverse events including deaths worldwide in 2007-2008. Here, rapid pyrolysis is integrated with direct analysis in real time (DART) mass spectrometry to rapidly screen major glycosaminoglycans, including heparin, chondroitin sulfate A, dermatan sulfate, and OSCS. The results demonstrate that, compared to traditional liquid chromatography-based analyses, pyrolysis mass spectrometry achieved at least 250-fold higher sample throughput and was compatible with samples volume-limited to about 300 nL. Pyrolysis yielded an abundance of fragment ions (e.g., 150 different m/z species), many of which were specific to the parent compound. Using multivariate and statistical data analysis models, these data enabled facile differentiation of the glycosaminoglycans with high throughput. After method development was completed, authentically contaminated samples obtained during the heparin crisis by the FDA were analyzed in a blinded manner for OSCS contamination. The lower limit of differentiation and detection were 0.1% (w/w) OSCS in heparin and 100 ng/μL (20 ng) OSCS in water, respectively. For quantitative purposes the linear dynamic range spanned approximately 3 orders of magnitude. Moreover, this chemical readout was successfully employed to find clues in the manufacturing history of the heparin samples that can be used for surveillance purposes. The presented technology and data analysis protocols are anticipated to be readily adaptable to other chemical and biochemical agents and volume-limited samples.