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New high-density polyethylene (HDPE) manufactured from different percentage of post-consumer recycled HDPE milk bottles was studied through two static and dynamic migration tests using saliva simulant to assess the potential hazard to children. Sixty-nine compounds were identified, including several additives used in PE synthesis such as alkanes, alkenes, antioxidants and plasticizers as well as non-intentionally added substances (NIAS) like degradation products such as 2,6-di-tert-butyl-1,4-benzoquinone, 2,4-di-tert-butylphenol, phenol, 2,5-bis(1,1-dimethylethyl)-, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and 3,5-di-tert-butyl-4-hydroxyacetophenone, or various residues from flavoring agents, cleaning products and essential oils. Some of these compounds as the isomers p and o t-butylcyclohexyl acetate, 3-Octanol, 3,7-dimethyl- and thujanol acetate (3-) pose a potential risk to children, as their concentrations exceed the recommended Cramer values for high percentages of recycling. This suggests improving recycling processes by incorporating advanced cleaning to remove residual products and contaminants.

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Ion mobility spectrometry (IMS) is a rapid gas-phase separation technique, which can distinguish ions on the basis of their size, shape, and charge. The IMS-derived collision cross section (CCS) can serve as additional identification evidence for the screening of environmental organic micropollutants (OMPs). In this work, we summarize the published experimental CCS values of environmental OMPs, introduce the current CCS prediction tools, summarize the use of IMS and CCS in the analysis of environmental OMPs, and finally discussed the benefits of IMS and CCS in environmental analysis. An up-to-date CCS compendium for environmental contaminants was produced by combining CCS databases and data sets of particular types of environmental OMPs, including pesticides, drugs, mycotoxins, steroids, plastic additives, per- and polyfluoroalkyl substances (PFAS), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), as well as their well-known transformation products. A total of 9407 experimental CCS values from 4170 OMPs were retrieved from 23 publications, which contain both drift tube CCS in nitrogen (DTCCSN2) and traveling wave CCS in nitrogen (TWCCSN2). A selection of publicly accessible and in-house CCS prediction tools were also investigated; the chemical space covered by the training set and the quality of CCS measurements seem to be vital factors affecting the CCS prediction accuracy. Then, the applications of IMS and the derived CCS in the screening of various OMPs were summarized, and the benefits of IMS and CCS, including increased peak capacity, the elimination of interfering ions, the separation of isomers, and the reduction of false positives and false negatives, were discussed in detail. With the improvement of the resolving power of IMS and enhancements of experimental CCS databases, the practicability of IMS in the analysis of environmental OMPs will continue to improve.

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The COVID-19 pandemic has led to children using polymeric FFP2 and polymeric surgical masks on a daily basis. Children often bite and suck on such masks as they wear them closed to their mouths. In this work, the migration of contaminants from printed and unprinted children`s masks to a saliva simulant has been studied. Liquid chromatography coupled to ion-mobility quadrupole time-of-flight mass spectrometry has been used for the detection and identification of non-volatile migrants. An orthogonal projection to latent structures - discriminant analysis (OPLS-DA) was applied to compare the data from the printed masks against the data from the unprinted ones. Headspace solid phase microextraction coupled to gas chromatography mass spectrometry was used to assess the migration of volatile compounds. Thirteen compounds were found in the masks with concentrations ranging from 5 ng/g to 254 ng/g. Toluene, chlorobenzene, irganox 1076 and 2-(2-butoxyethoxy)ethyl acetate were all found to migrate from the masks studied. Moreover, differences between the migrants from printed and unprinted FFP2 masks were found. Octocrylene, 4-(dimethylamine)benzoate, methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris(3-methylphenyl)phosphate were found to migrate only from printed masks. Toluene that migrated from all the masks studied and tris(3-methylphenyl)phosphate, that migrated only from printed masks, have been listed as hazardous priority substances.

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The identification of migrates from food contact materials (FCMs) is challenging due to the complex matrices and limited availability of commercial standards. The use of machine-learning-based prediction tools can help in the identification of such compounds. This study presents a workflow to identify nonvolatile migrates from FCMs based on liquid chromatography-ion mobility-high-resolution mass spectrometry together with in silico retention time (RT) and collision cross section (CCS) prediction tools. The applicability of this workflow was evaluated by screening the chemicals that migrated from polyamide (PA) spatulas. The number of candidate compounds was reduced by approximately 75% and 29% on applying RT and CCS prediction filters, respectively. A total of 95 compounds were identified in the PA spatulas of which 54 compounds were confirmed using reference standards. The development of a database containing predicted RT and CCS values of compounds related to FCMs can aid in the identification of chemicals in FCMs.

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The use of ion mobility separation (IMS) in conjunction with high-resolution mass spectrometry has proved to be a reliable and useful technique for the characterization of small molecules from plastic products. Collision cross-section (CCS) values derived from IMS can be used as a structural descriptor to aid compound identification. One limitation of the application of IMS to the identification of chemicals from plastics is the lack of published empirical CCS values. As such, machine learning techniques can provide an alternative approach by generating predicted CCS values. Herein, experimental CCS values for over a thousand chemicals associated with plastics were collected from the literature and used to develop an accurate CCS prediction model for extractables and leachables from plastic products. The effect of different molecular descriptors and machine learning algorithms on the model performance were assessed. A support vector machine (SVM) model, based on Chemistry Development Kit (CDK) descriptors, provided the most accurate prediction with 93.3% of CCS values for [M + H]+ adducts and 95.0% of CCS values for [M + Na]+ adducts in testing sets predicted with <5% error. Median relative errors for the CCS values of the [M + H]+ and [M + Na]+ adducts were 1.42 and 1.76%, respectively. Subsequently, CCS values for the compounds in the Chemicals associated with Plastic Packaging Database and the Food Contact Chemicals Database were predicted using the SVM model developed herein. These values were integrated in our structural elucidation workflow and applied to the identification of plastic-related chemicals in river water. False positives were reduced, and the identification confidence level was improved by the incorporation of predicted CCS values in the suspect screening workflow.

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The chemicals in food contact materials (FCMs) can migrate into food and endanger human health. In this study, we developed a database of traveling wave collision cross section in nitrogen (TWCCSN2) values for extractables and leachables from FCMs. The database contains a total of 1038 TWCCSN2 values from 675 standards including those commonly used additives and nonintentionally added substances in FCMs. The TWCCSN2 values in the database were compared to previously published values, and 85.7, 87.7, and 64.9% [M + H]+, [M + Na]+, and [M - H]- adducts showed deviations <2%, with the presence of protomers, post-ion mobility spectrometry dissociation of noncovalent clusters and inconsistent calibration are possible sources of CCS deviations. Our experimental TWCCSN2 values were also compared to CCS values from three prediction tools. Of the three, CCSondemand gave the most accurate predictions. The TWCCSN2 database developed will aid the identification and differentiation of chemicals from FCMs in targeted and untargeted analysis.

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The synthetic chemicals in food contact materials can migrate into food and endanger human health. In this study, the traveling wave collision cross section in nitrogen values of more than 400 chemicals in food contact materials were experimentally derived by traveling wave ion mobility spectrometry. A support vector machine-based collision cross section (CCS) prediction model was developed based on CCS values of food contact chemicals and a series of molecular descriptors. More than 92% of protonated and 81% of sodiated adducts showed a relative deviation below 5%. Median relative errors for protonated and sodiated molecules were 1.50 and 1.82%, respectively. The model was then applied to the structural annotation of oligomers migrating from polyamide adhesives. The identification confidence of 11 oligomers was improved by the direct comparison of the experimental data with the predicted CCS values. Finally, the challenges and opportunities of current machine-learning models on CCS prediction were also discussed.

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Biodegradable materials are increasingly being used in manufacturing processes due to their environmental benefits. In this work, a study has been performed to assess the migration of compounds from biodegradable multilayer teacups to a tea solution. Liquid chromatography in conjunction with ion-mobility quadrupole time-of-flight mass spectrometry has been used for the elucidation of non-volatile compounds. An orthogonal projection to latent structures-discriminant analysis has been carried out to compare the tea after migration against untreated tea used as blank. Headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry has been optimised to analyse the migration of volatile compounds. Eight migrants were identified in the tea, six of which were non-intentionally added oligomers. The degree of migration for hot tea ranged from 0.05 and 4.68 mg/kg, exceeding the specific migration limit. Nevertheless, the migration to cold tea was an order of magnitude lower (between 0.003 and 0.56 mg/kg).

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An exhaustive migration study of eight corks, made of ethylene-vinyl acetate, was carried out to identify any non-volatile and volatile compounds using an untargeted approach. The challenge associated with the structural elucidation of unknowns was undertaken using both ultra-high-performance liquid chromatography coupled to an ion-mobility separation quadrupole-time of flight mass spectrometer and gas chromatography mass spectrometry. A total of fifty compounds were observed to migrate from the corks, and among these additives such as antioxidants (Butyl 4-hydroxybenzoate, Irganox 1010, Irganox 1075, Irgafos 168 and BHT) or lubricants (EBO and octadecanamide, N,N'-1,2-ethanediylbis-) were identified. A high proportion (84%) of the detected compounds was non-intentionally added substances (NIAS), and included several cyclic oligomers with different chain sequences. NIAS, such as 2,6-bis(1,1-dimethylethyl)-4-ethyl and 7,9-ditert-butyl-1-oxaspiro[4.5]deca-6,9-diene-2,8-dione, break-down products, including hexa-, hepta- and nonadecanamide, N,N'-1,2-ethanediylbis-, and oxidation products were also identified. One cork was found to be unsuitable for use as a food contact material.

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The characterization and quantification of phenolic compounds in bearberry leaves were performed using hyphenated ion mobility spectroscopy (IMS) and a quadrupole time-of-flight mass spectrometer. A higher identification confidence level was obtained by comparing the measured collision cross section (TWCCSN2) with predicted values using a machine learning algorithm. A total of 88 compounds were identified, including 14 arbutin derivatives, 33 hydrolyzable tannins, 6 flavanols, 26 flavonols, 9 saccharide derivatives, and glycosidic compounds. Those most reliably reproduced in all samples were quantified against respective standards. Arbutin (47-107 mg/g), 1,2,3,4,6-pentagalloylglucose (6.6-12.9 mg/g), and quercetin 3-galactoside/quercetin 3-glucoside (2.7-5.7 mg/g) were the most abundant phenolic components in the leaves. Quinic acid and ellagic acid were also detected at relatively high concentrations. The antioxidant activity of the most abundant compounds was evaluated. A critical view of the advantages and limitations of traveling wave IMS and CCS for the discovery of natural products is given.

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Polyurethane adhesives are used to bond agglomerated cork and natural disk cork to produce cork stoppers that are used in champagne bottles. These adhesives are manufactured by reacting polyols with an excess of diisocyanates. Isocyanates are highly reactive compounds that have a propensity to form non-intentionally added substances (NIAS) in the end product. In this work, ion mobility-time of flight-mass spectrometry was used to elucidate such NIAS, through the comparison of accurate mass spectra with the fragmentation patterns of proposed candidates. Twelve neo-formed compounds, including amines, amides and urethanes, resulting from the reaction of isocyanates with acetic acid and ethanol used as food simulants, were identified. Additionally, markers from champagne vs. champagne after its exposure to the adhesive were investigated using the supervised multivariate analysis method of Orthogonal Projection to Latent Structures - Discriminant Analysis. Four neo-formed compounds, resulting from the reaction of diisocyanates with malic acid or tartaric acid contained in the champagne, were identified for the first time in this work. All of the compounds identified were subsequently quantified using ultra-high pressure liquid chromatography coupled to a triple quadrupole mass spectrometer. Limits of detection were below 5 µg/kg in the food simulants and below 30 µg/kg in champagne samples. Migration levels ranged from 70 to 721 µg/kg, with most of them exceeding the specific migration limit established for Cramer class III compound (90 µg/kg).

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Oligomers, are, in general, unknown components of the polymer. These oligomers can migrate from the polymer into the food and become a non-intentionally added substance to the food. In this work, ion mobility time-of-flight mass spectrometry has been used to identify oligomers migrating from kitchenware. The structure elucidation of oligomers from polyamide 6 and polyamide 66 was achieved through the analysis of accurate m/z values of adducts and collision cross section values of precursor ions together with high-energy fragmentation patterns. Additionally, a method to extract oligomers from sunflower oil, cooked beans, soup and whole milk has been developed. Extraction recoveries ranged from 87 to 102% and limits of detection were from 0.03 to 0.11 mg/kg. It was observed that the migration from kitchenware to real food was below the specified migration limit of 5 mg/kg. However, this limit was exceeded for food simulants, which therefore overestimated the oligomer migration.

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Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the volatile compounds of minced pork meat during storage. The origin of aromatic hydrocarbons in pork was verified by migration test. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were applied to characterize the profile of volatile compounds in pork meat and identify the potential volatile markers associated with the spoilage of pork. A total of 41 compounds were identified. Migration test showed that the aromatic hydrocarbons in raw pork are from packaging. Three compounds: ethanol, 2,3-butanediol and 2-ethyl-1-hexanol were selected based on the loading plot and their variables importance in the projection (VIP) values, since they contribute mainly to the discrimination of pork with different storage times. These compounds can be used as additional indicators for quality control of pork.

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The total phenolic content (TPC) and antioxidant capacity have been considered as important quality parameters for plant extracts. In this study, bearberry leaves were regarded as studied subject and a reliable method was established to predict the TPC and antioxidant capacity of bearberry leaves. Ultraviolet-visible spectrometry (UV-Vis) and ultra high pressure liquid chromatography coupled to time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) were used to provide spectral fingerprinting and metabolomic profiling. The data obtained (separately and merged) were used to build partial least squares (PLS) regression model. The PLS model built by using ultraviolet-visible spectra provided a satisfactory prediction result. Mid-level data fusion using the scores significantly improved the performance of PLS regression model, the residual predictive deviations (RPDs) for TPC and α, α-diphenyl-ß-picrylhydrazyl (DPPH) were 6.258 and 6.699, respectively, showing an excellent predictive ability. This study proved the potential of combination of UV-Vis spectrometry and UHPLC/Q-TOF-MS in the prediction of TPC and antioxidant capacity of plant extracts.

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Seven commercial samples, consisted of plastic bags, tetrabrik and box, were evaluated by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) to find the compounds responsible for off-odors in different PP, PE, multilayer cardboard and paper materials used for food contact. Migration assays were carried out with Tenax as food simulant to analyze the food safety as well as to evaluate the odor intensity after migration assay. Forty six compounds with characteristic odors were directly found in the materials studied. The strongest odors identified were acetic, propanoic and butyric with vinegar and rancid odors and octanal, nonanal and decanal with fat/soup odors, all of them found in PP and PE samples. Trimethylbenzenes with solvent and oily odors as well as terpenes with weakly woody odors were found in cardboard and paper materials. After migration, all compounds were below the European Legislation limits and maximum migration values recommended by Cramer. However propanoic, acetic and butyric acid as well as aldehydes compounds, phenol and 1-octanol were detected by sniffers, after migration assay, with high modified frequency (between 50 and 78%), what could change the organoleptic properties of packaged food.

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Sealants, incorporated in the lids of food cans to ensure the can is hermetically sealed, are formulated from a wide variety of compounds. These compounds and associated non-intentionally added substances (NIAS) could migrate to the food contained in the can. In this work, ion mobility quadrupole time-of-flight mass spectrometry coupled to ultra-high performance liquid chromatography (UHPLC-IM-QTOF-MS) has been used to obtain ion mobility filtered extracted ion chromatograms. Subsequently, accurate mass precursor ions and their fragments have been used to identify the compounds migrating from the sealant to the content of the cans. Moreover, the correlation between the collision cross-section (CCS) values and m/z of the compounds was used to increase the level of confidence of the identification. Seven compounds were found to have migrated to the food simulants. The compounds bis(2-hydroxy-3-tert-butyl-5-methylphenyl)dicyclopentane,1-tetradecanesulfonic acid, 1-pentadecanesulfonic acid, 1-hexadecanesulfonic acid and naphthalene-2-sulfonic acid (whose migration was over the specific migration limit established by the European Regulation 10/2011/EU) were identified as NIAS in the food simulants studied.

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Nontarget analysis of nonvolatile substances in complex samples is a very challenging task that requires powerful analytical techniques and experience of analyzing such samples. An extensive study was conducted in order to identify nonintentionally added substances (NIAS) migrating from 18 polyethylene (PE) samples intended to be in contact with food. The migration assays were performed in five simulants and analyzed by ultrahigh-performance liquid chromatography (UPLC) coupled to an ion-mobility separation (IMS) quadrupole-time-of-flight (QTOF) mass spectrometer. This experimental setup provides a novel and powerful tool for this type of nonvolatile and nontargeted analysis. Thirty-five compounds were identified, 17 of which were NIAS. Methyl and ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate were found to be degradation products of either Irganox 1010 or Irganox 1076. Additionally, breakdown products including hexa-heptadecanamide, N,N'-1,2-ethanediylbis- and 11-eicosenamide were identified together with impurity reaction products, e.g., dibutyl amine or compounds of unknown origin like phosphine oxide, tributyl-. Forty-five percent of the detected compounds are in the positive list contained in Regulation 10/2011/EU, and their migration values were below their specific migration limits. The risk assessment for the rest of the compounds was carried out by comparing their migration values to the maximum concentration recommended by Cramer, e.g., ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate and benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 1,1'-[2,2-bis(hydroxymethyl)-1,3-propanediyl] ester (both class II toxicity), heptadecanamide, N,N'-1,2-ethanediylbis-, and phosphine oxide, tributyl- (both class III toxicity) were above the maximum concentration values for three samples that were migrated to ethanol 95%, and therefore, these samples are not suitable for food contact. The analytical tools and procedures used in this study are presented and discussed in detail.

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A flexible multilayer with selenium nanoparticles incorporated has been used to build an antioxidant packaging. The oxidation of hazelnuts, walnuts, and potato chips was tested at laboratory scale. Hexanal released by the nuts, fatty acids oxidation study, TBARS (thiobarbituric acid reactive substances), and tasting were compared to study the oxidation of foods packaged with this antioxidant packaging. Finally, TBARS method in combination with tasting were selected due to their simplicity and accuracy. It was found that hazelnuts packaged in nanoSe active bags released around 20% less malonaldehyde (MDA) than the blanks. In the case of the walnuts, the active ones released 25% less MDA than the blanks. As for potato chips, the improvement was around 22%. Finally, an industrial study was done. Cooked ham, chicken, and a ready-to-eat vegetable mixture seasoned with butter were industrially packaged with the new antioxidant material and improvements higher than 25% were obtained.

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Migration of non volatile compounds from twenty six PP films used as food contact materials has been studied in four simulants (ethanol 95% and 10%, acetic acid 3% and Tenax ®) and analyzed by UPLC-MS/QTOF. Seventy six compounds have been identified, where 76% of them were non-intentionally added substances (NIAS) coming from degradation of additives used, such as methyl or ethyl or hexyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) from irganox 1076 and irganox 1010 degradation; or impurities such as N,N-bis(2-hydroxyethyl) amines, or compounds of unknown origin, like hydro-ceramides. The most common compounds found were glyceryl monostearate or monopalmitate, erucamide, irganox 1010, irgafos 168, irgafos 168 OXO, N,N-bis(2-hydroxyethyl) tridecylamine and N,N-bis(2-hydroxyethyl) pentadecylamine. Six films didn't comply with the European Regulation Nº 10/2011/EU, where irganox 1010 and the group of N,N-bis(2-hydroxyethyl) amines exceeded their SMLs. Other films surpassed the maximum concentration recommended by Cramer for the compounds of class II (degradation products) or III (amide compounds) when ethanol 95% was used as simulant.

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Migration from a multilayer plastic material intended for food contact showed that 2,4,7,9-tetramethyl-5-decyne-4,7-diol mixture (surfynol), used as a surfactant in the adhesive employed to build the multilayer, was transferred to water and other food simulants in contact with the plastic. When these multilayer plastics were used for containing seminal doses for artificial insemination, it was found that fertility was seriously damaged in terms of motility, acrosome integrity, mitochondrial activity and penetration capacity in the cells, thus affecting male fertility. Quantitative proteomic analysis of exposed germinal cells demonstrated the inhibition of key proteins involved in the fertilization capacity by affecting the cytoskeleton, sperm motility, the energy machinery and sperm defense mechanisms against oxidation, therefore confirming the surfactant-induced male infertility. These results open up new and interesting perspectives for the study of reprotoxicity caused by different chemicals common in our daily lives. SIGNIFICANCE: This paper demonstrates the toxicity for reproduction of a common surfactant used in food packaging and the scientific reasons why the sperm loses reproductive capacity in presence of this chemical. So, the surfactant affects the male fertility. The surfactant is present in many adhesives used either for building multilayer materials or to glue paper and plastic in food packaging. This is the first time that reprotoxicity is demonstrated for this compound. According to the theoretical approach Threshold of Toxicological Concern (TTC) the compound is highly toxic but experimental data did not exist so far. The study described in this paper and the results obtained open a door to further research in which male infertility caused by chemicals could be demonstrated.

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