Liquid chromatography–full scan-high resolution mass spectrometry-based method towards the comprehensive analysis of migration of primary aromatic amines from food packaging

Tracking Aromatic Amines from Sources to Surface Waters

This review examines the environmental occurrence and fate of aromatic amines (AAs), a group of environmental contaminants with possible carcinogenic and mutagenic effects. AAs are known to be partially responsible for the genotoxic traits of industrial wastewater (WW), and AA antioxidants are acutely toxic to some aquatic organisms. Still, there are gaps in the available data on sources, occurrence, transport, and fate in domestic WW and indoor environments, which complicate the prevention of adverse effects in aquatic ecosystems. We review key domestic sources of these compounds, including cigarette smoke and grilled protein-rich foods, and their presence indoors and in aquatic matrices. This provides a basis to evaluate the importance of nonindustrial sources to the overall environmental burden of AAs. Appropriate sampling techniques for AAs are described, including copper-phthalocyanine trisulfonate materials, XAD resins in solid-phase extraction, and solid-phase microextraction methods, which can offer insights into AA sources, transport, and fate. Further discussion is provided on potential progress in the research of AAs and their behavior in an aim to support the development of a more comprehensive understanding of their effects and potential environmental risks.

A screen-printed electrode modified with gold nanoparticles/cellulose nanocrystals for electrochemical detection of 4,4′-methylene diphenyl diamine

Developing simple, cost-effective, easy-to-use, and reliable analytical devices if of utmost importance for the food industry for rapid in-line checks of their products that must comply with the provisions set by the current legislation. The purpose of this study was to develop a new electrochemical sensor for the food packaging sector. More specifically, we propose a screen-printed electrode (SPE) modified with cellulose nanocrystals (CNCs) and gold nanoparticles (AuNPs) for the quantification of 4,4'-methylene diphenyl diamine (MDA), which is one of the most important PAAs that can transfer from food packaging materials into food stuffs. The electrochemical performance of the proposed sensor (AuNPs/CNCs/SPE) in the presence of 4,4'-MDA was evaluated using cyclic voltammetry (CV). The modified AuNPs/CNCs/SPE showed the highest sensitivity for 4,4'-MDA detection, with a peak current of 9.81 μA compared with 7.08 μA for the bare SPE. The highest sensitivity for 4,4'-MDA oxidation was observed at pH = 7, whereas the detection limit was found at 57 nM and the current response of 4,4'-MDA rose linearly as its concentration increased from 0.12 μM to 100 μM. Experiments using real packaging materials revealed that employing nanoparticles dramatically improved both the sensitivity and the selectivity of the sensor, which can be thus considered as a new analytical tool for quick, simple, and accurate measurement of 4,4'-MDA during converting operations.

Adsorptive removal of aromatic diamines from water using metal-organic frameworks functionalized with a nitro group

Adsorptive removal of aromatic diamines such as methylenedianiline (MDA) and p-phenylenediamine (PPD) was firstly investigated with nitro-functionalized metal-organic frameworks (MOFs, MIL-101(Cr)-NO₂). The MIL-101(Cr)-NO₂ showed much better performances in the removal of MDA and PPD, in both adsorption capacity and kinetics, than any other adsorbents. For example, MIL-101(Cr)-NO₂ had a much higher maximum adsorption capacity for MDA (1111 mg·g^-1) than activated carbon (208 mg·g^-1) or a reported adsorbent (391 mg·g^-1). Based on experimental results, hydrogen bonding (especially, via the formation of a 6-membered ring (6-MR) between -NO₂ of the adsorbent and -NH₂ of the adsorbates) could be suggested as the main mechanism to interpret the noticeable adsorption of the diamines. Importantly, this is the first example to confirm that MOFs with nitro group can be a competitive adsorbent to remove organics composed of amino group, especially via making 6-MR through hydrogen bonding. Higher adsorption of MDA than that of PPD over MIL-101(Cr)-NO₂ might be explained with π-π interaction between aromatic rings (π-lean aromatics of MOF and π-rich aromatics of the adsorbates). Moreover, MIL-101(Cr)-NO₂ could be recycled after simple washing, suggesting the potential use of the MOF in adsorptive purification of contaminated water with organics with amino groups.

Ultra-high-performance liquid chromatography-atmospheric pressure ionization-tandem mass spectrometry method for the migration studies of primary aromatic amines from food contact materials

This work describes the development of an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of 23 primary aromatic amines (PAAs) that can potentially migrate from food contact materials. The chromatographic separation was performed in a pentafluorophenylpropyl (PFPP) column achieving the separation of all PAAs in less than 6.5 min using water to acetonitrile (0.1% acetic acid in both solvents) as mobile phase and a gradient elution. The feasibility of atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) was evaluated as alternative to electrospray ionization (ESI) for the analysis of PAAs. Results showed that for most of the compounds, better responses were obtained with APCI, which shows the advantage of being less susceptible to matrix effects. Tandem mass spectrometry (MS/MS) fragmentation studies of [M + H]+ allowed for the selection of the two most characteristic and abundant product ions of the 23 PAAs which led to the development of a selective and sensitive UHPLC-APCI-MS/MS method with limits of detection ranging from 0.2 to 2 μg kg-1. Moreover, intra-day and inter-day precisions of the method in terms of relative standard deviation (RSD%) were lower than 10% and 15%, while trueness as relative error was <15% for most of the compounds. The UHPLC-APCI-MS/MS method was applied to the analysis of twenty black Nylon kitchenware samples that were submitted to migration tests using food simulant B (3% acetic acid, w/v), and the presence of PAAs were detected in eighteen samples at concentrations above the legislated limit (2 μg kg-1 of food or food simulants).

New and efficient magnetic nanocomposite extraction using multifunctional deep eutectic solvent based on ferrofluid and vortex assisted-liquid-liquid microextraction: Determining primary aromatic amines (PAAs) in tetra-packed fruit juices

In this work, a novel magnetic nanocomposite solvent (MNCS) based on ferrofluid and multifunctional deep eutectic solvent (MDES) was synthesized and applied in vortex assisted-liquid-liquid microextraction (VA-LLME). The ferrofluid has been composed from zirconium phosphate (modified magnetic graphene oxide) and tetrabutylammonium bromide-octanoic acid deep eutectic solvent (MGO/α-ZrP@TBAB-OA). This efficient method was employed to determine primary aromatic amines including aniline, 4-methoxyanniline, 4,4'-diaminodiphenylmethane, orthotoluidine, 2,6-dimethylaniline, 2-naphtylamine in tetra-packed juice samples. The proposed method showed the excellent extraction efficiency of PAAs according to strong interactions of new extraction solvent including electrostatic, π-π, and hydrogen bonding attractions. The found levels of PAAs are lower than the limit of quantifications (2.0 µg L^-1). Therefore, the migration of PAAs from packaging to the juice samples is lower than permitted level (<10 µg kg^-1). The results indicated high potential use of the offered method to analyze aromatic amine compounds in foodstuff and biologic samples in the future.

Atlantic cod (Gadus morhua) embryos are highly sensitive to short-term 3,4-dichloroaniline exposure

3,4-dichloroaniline (3,4-DCA) is one of the most widely produced anilines world-wide, used in plastic packaging, fabrics, pharmaceuticals, pesticides, dyes and paints as well as being a degradation product of several pesticides. 3,4-DCA has been detected in freshwater, brackish and marine environments. Although freshwater toxicity thresholds exist, very little toxicological information is available on marine and cold-water species. In this study, we exposed Atlantic cod (Gadus morhua) embryos (3-7 days post fertilization) to 3,4-DCA concentrations ranging from 8-747 μg/L for 4 days followed by a recovery period in clean sea water until 14 days post fertilization (dpf). The cod embryos were significantly more sensitive to acute 3,4-DCA exposure compared to other species tested and reported in the literature. At the highest concentration (747 μg/L), no embryos survived until hatch, and even at the lowest concentration (8 μg/L), a small, but significant increase in mortality was observed at 14 dpf. Delayed and concentration-dependent effects on surviving yolk-sac larvae, manifested as cardiac, developmental and morphometric alterations, more than a week after exposure suggest potential long-term effects of transient embryonic exposure to low concentrations of 3,4-DCA.

A liquid chromatography-tandem mass spectrometry method for the analysis of primary aromatic amines in human urine

Aromatic amines are widely used in personal care products and human exposure to this class of chemicals is widespread. Bioanalytical methods to determine trace levels of aromatic amines in human urine are scarce. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to determine 39 primary aromatic amines (AAs) along with nicotine and cotinine in human urine. Chromatographic separation of the 41 analytes was achieved on an Ultra Biphenyl (100 mm × 2.1 mm, 5 µm) column. Mass spectrometry was operated in electrospray ionization positive ion multiple reaction monitoring (MRM) mode. The method exhibited excellent linear dynamic range (0.1-50 ng/mL) with correlation coefficients (r) > 0.999 for all analytes. Urine samples (2 mL) were hydrolyzed using 10 M NaOH at 95 °C for 15 h and target analytes were extracted using methyl-tert-butyl ether (MTBE). Addition of 15 µL of 0.25 M HCl to the sample extracts improved the recoveries of several target analytes. The method was validated through the analysis of fortified quality control (QC) samples and a certified standard reference material (SRM). Relative recoveries (%) of target analytes fortified in QC samples were in the range of 75-114% for 37 of the 41 analytes while the other analytes exhibited lower recoveries (16-74%). The limits of detection (LOD) and limits of quantification (LOQ) of target analytes were in the range of 0.025-0.20 ng/mL and 0.1-1.0 ng/mL, respectively. Intra-day and inter-day precision of the method assessed through the analysis of fortified urine QC samples at three different concentrations were < 11.7% and < 15.9% (measured as RSD), respectively. The method was applied in the analysis of urine samples from the general population and known smokers; aniline, para-anisidine, para-toluidine, ortho/meta-toluidine, 3-chloroaniline, 4-chloroaniline, 3,4-dichloroaniline, and 4,4'-methylenedianiline were found in all smoker's urine at sum concentrations ranging from 0.04 to 9.16 ng/mL.

Leaching and extraction of additives from plastic pollution to inform environmental risk: A multidisciplinary review of analytical approaches

Plastic pollution is prevalent worldwide and has been highlighted as an issue of global concern due to its harmful impacts on wildlife. The extent and mechanism by which plastic pollution effects organisms is poorly understood, especially for microplastics. One proposed mechanism by which plastics may exert a harmful effect is through the leaching of additives. To determine the risk to wildlife, the chemical identity and exposure to additives must be established. However, there are few reports with disparate experimental approaches. In contrast, a breadth of knowledge on additive release from plastics is held within the food, pharmaceutical and medical, construction, and waste management industries. This includes standardised methods to perform migration, extraction, and leaching studies. This review provides an overview of the approaches and methods used to characterise additives and their leaching behaviour from plastic pollution. The limitations of these methods are highlighted and compared with industry standardised approaches. Furthermore, an overview of the analytical strategies for the identification and quantification of additives is presented. This work provides a basis for refining current leaching approaches and analytical methods with a view towards understanding the risk of plastic pollution.

Determination of primary aromatic amines from cooking utensils by capillary electrophoresis-tandem mass spectrometry

This paper describes a fast, sensitive, environment-friendly method for the determination of 19 primary aromatic amines (PAAs) in cooking utensils by capillary zone electrophoresis coupled with tandem mass spectrometry. The best electrophoretic separation of PAAs was obtained in 0.1 mol l^-1 formic acid (pH 2.4) as the background electrolyte, fused silica capillary (67 cm) with a run time below 6 min. The proposed method presented a linear calibration with correlation coefficients higher than 0.99 and reproducibility in a range of 1-25%. Limits of detection were in the range of 0.2-1.3 μg kg^-1 and recoveries were in a range of 85-120% for all the PAAs. The validated method was employed to determine PAAs on 36 samples of cooking utensils using acetic simulant. The results showed that 4,4'-diaminodiphenylmethane and aniline being the most frequently found PAAs in these samples and 28% of cooking utensils were not compliant.

Effects of 3,4-dichloroaniline (3,4-DCA) and 4,4'-methylenedianiline (4,4'-MDA) on sex hormone regulation and reproduction of adult zebrafish (Danio rerio)

3,4-dichloroaniline (3,4-DCA) and 4,4'-methylenedianiline (4,4'-MDA) have been widely used in manufacture of many industrial and consumer products, and hence often detected in aquatic environment. Reproductive toxicity of aniline and its derivatives in aquatic organisms has been suggested, however, knowledge on the endocrine disruption potentials and toxicological consequences of both anilines are not well understood, especially in fish. In this study, we aimed to understand the effects of 3,4-DCA and 4,4'-MDA on sex hormone regulation and reproduction of adult zebrafish (Danio rerio). Following 21 d exposure, significant decreases of the reproduction were observed at 0.38 mg/L 3,4-DCA, and 4.6 mg/L 4,4'-MDA. Moreover, plasma concentrations of testosterone (T) and 17β-estradiol (E2) level were significantly decreased in both male and female fish following the exposure. The sex hormone changes could be explained by the regulatory changes of the genes along the hypothalamic-pituitary-gonadal (HPG) axis, including significant down-regulation of steroidogenic acute regulatory protein (star) and cytochrome P450 family 19 subfamily A (cyp19a) genes in the gonad. Moreover, inhibition of gonadotropin hormone signaling and prostaglandin-endoperoxide synthase 2 (ptgs2) gene expression were observed, suggesting potential disruption of oocyte maturation and ovulation by the exposure. Our observations indicate that 3,4-DCA and 4,4'-MDA can impair reproduction of zebrafish potentially through disruption of steroid hormone synthesis and ovulation.

From pigments to coloured napkins: comparative analyses of primary aromatic amines in cold water extracts of printed tissues by LC-HRMS and LC-MS/MS

A collaborative study was conducted to understand the correlation between pigments purity profile (primary aromatic amine content of the pigments) and the behaviour of these PAAs during cold water extraction (CWE) tests according to EN 645. From a selection of organic pigments based on seven colour indexes (PR122, PR184, PO13, PY74, PY111, PY138 and PY155), the pigment purity profile was established according to European Resolution AP (89) 1, then mono-pigmented inks were prepared and napkins printed with these inks. In a second step, cold water extraction and PAA determination were performed by two independent laboratories. In one laboratory, an analytical method based on LC-MS/MS was used, whereas in the other laboratory a method based on LC-HRMS using Orbitrap technology was developed for the simultaneous analysis of 35 PAAs. Good qualitative results were obtained if we consider that at significant levels the PAAs were positively detected in both laboratories, except for 3-amino-4-methoxybenzanilide and 8-amino-2-methyl-quinoline, for which inter-laboratory differences were observed. It was also shown that no contamination from unexpected PAAs was detected. The comparison between pigment analysis and CWE results shows that if the pigment purity profile is of major importance, other parameters such as pigment surface treatment, ink grinding process or ink formulation could have an important influence on the CWE results. For such sensitive applications, for example napkins or other Food Contact Materials (FCM), it is therefore recommended not only to select a pigment with a good purity profile but also to test the pigment in the final application. Finally, this work highlights the difficulty of validating a product on a single analysis and shows the importance of a multilevel global assessment on worst case application.

Colorimetric indicators for volatile amines based on succinic anhydride (SAh)-grafted poly (lactic acid) (PLA)

Smart materials that can undergo changes in color upon the detection of amines have the potential to provide information on the freshness of fish and meat. To engineer a material that undergoes a change in color upon exposure to biogenic amines, succinic anhydride functional groups - which are deprotonated in the presence of amines - are grafted onto a biopolymer poly(lactic acid) backbone. This material is then blended with a pH sensitive dye, yielding a material that shows a highly specific response to amines. In this system, the reaction between SAh and amines protonates the dye and leads to an irreversible change in color in the indicators. The resulting change in color was recorded and monitored with standardized photos and UV-Vis spectroscopy. Initially, indicators of different degrees of SAh (from 5 wt% to 45 wt%) grafted onto PLA were exposed to the vapours from a 400 ppm amine solution. The samples with higher degrees of grafting underwent the most visible changes in color. A more detailed study of the effect of temperature and amine concentration was performed on indicators with 30 wt% SAh. The limits of detection, half-time and kinetics of the response are also presented. Higher temperatures and concentrations were found to increase the degree of the color change while decreasing the half-time of the response of the indicators. This work shows potential opportunities for the development of simple real-time amine indicators.

Recent Trends in the Analysis of Chemical Contaminants in Beverages

Chemical contaminants should not be present in beverages for human consumption, but could eventually be ingested by consumers as they may appear naturally from the environment or be produced by anthropogenic sources. These contaminants could belong to many different chemical sources, including heavy metals, amines, bisphenols, phthalates, pesticides, perfluorinated compounds, inks, ethyl carbamate, and others. It is well known that these hazardous chemicals in beverages can represent a severe threat by the potential risk of generating diseases to humans if no strict quality control is applied during beverages processing. This review compiles the most updated knowledge of the presence of potential contaminants in various types of beverages (both alcoholic and non-alcoholic), as well as in their containers, to prevent undesired migration. Special attention is given to the extraction and pre-concentration techniques applied to these samples, as well as to the analytical techniques necessary for the determination of chemicals with a potential contaminant effect. Finally, an overview of the current legislation is carried out, as well as future trends of research in this field.

Thin-layer chromatography combined with surface-enhanced Raman scattering for rapid detection of benzidine and 4-aminobiphenyl in migration from food contact materials based on gold nanoparticle doped metal-organic framework

In this work, a rapid and sensitive thin-layer chromatography combined with surface-enhanced Raman spectroscopy method was established for rapid detection of benzidine and 4-aminobiphenyl in migration from food contact materials based on Au nanoparticle doped metal-organic framework. Benzidine and 4-aminobiphenyl were firstly separated by thin-layer chromatography to solve the limitation of their overlapping Raman peaks. Then the target molecules were monitored by adding AuNPs/MIL-101(Cr) on the sample spots. Under the optimum conditions, the concentration of benzidine and 4-aminobiphenyl can be quantitatively measured in the range of 2.0-20.0 and1.0-15.0 μg/L, respectively with good linear relationship, and the limits of detection were 0.21 and 0.23 μg/L, respectively. Furthermore, the developed method was applied to analyze benzidine and 4-aminobiphenyl in migration of different food contact materials. The recoveries of benzidine and 4-aminobiphenyl for migration of food contact materials, including paper cups, polypropylene food containers, and polyethylene glycol terephthalate bottles, were 80.6-116.0 and 80.7-118% with relative standard deviations of 1.1-9.1 and 3.1-9.9%, respectively. Surface-enhanced Raman scattering detection was performed conveniently in the on-plate mode without additional elution process. The method shows great potential in rapid monitoring of hazardous substances with overlapping characteristic Raman peaks in food contact materials.

Endocrine disruption by several aniline derivatives and related mechanisms in a human adrenal H295R cell line and adult male zebrafish

Aniline and aniline derivatives have been widely used in the production of pesticides, pharmaceuticals, cosmetic, dyes, rubber, and adhesives products. These chemicals can easily be released into the environment through industrial and municipal discharges or as degradation byproducts. Several studies have suggested that aniline and some of its derivatives could cause reproductive toxicity in aquatic organisms. However, knowledge on the endocrine disruption potentials of these chemicals is limited only to aniline and associated mechanisms are rarely investigated. The objective of this study was to investigate the potential of major aniline derivatives, i.e., 3,4-dichloroaniline (3,4-DCA), 1-naphthylamine (1-NPA), and 4,4'-methylenedianiline (4,4'-MDA), to disrupt sex steroid production and other biological processes. For this purpose, the human adrenal H295R cell line and adult male zebrafish (Danio rerio) were used. In the H295R cell line, all tested aniline derivatives decreased testosterone (T) levels. Regulatory changes of several steroidogenic genes, i.e., down-regulation of StAR or CYP17 genes, and up-regulation of CYP19A, observed in the H295R cells could explain the sex hormone disruption. In male zebrafish, generally similar directions of changes, i.e., decreases in T levels and increased E2/T ratios, were observed. Again, down-regulation of key steroidogenic genes such as cyp17 or 3β-hsd, but slight up-regulation of cyp19a gene observed in the fish could explain the sex hormone changes. The results of our study demonstrate that all tested aniline derivatives could influence steroidogenesis and disrupt sex hormone balance toward reduced androgenicity. Consequences of anti-androgenicity following long-term exposure warrant further investigation.

Amine Responsive Poly(lactic acid) (PLA) and Succinic Anhydride (SAh) Graft-Polymer: Synthesis and Characterization

Amines are known to react with succinic anhydride (SAh), which in reactions near room temperature, undergoes a ring opening amidation reaction to form succinamic acid (succinic acid-amine). In this work, we propose to form an amine-responsive polymer by grafting SAh to a poly(lactic acid) (PLA) backbone, such that the PLA can provide chemical and mechanical stability for the functional SAh during the amidation reaction. Grafting is performed in a toluene solution at mass content from 10 wt% to 75 wt% maleic anhydride (MAh) (with respect to PLA and initiator), and films are then cast. The molecular weight and thermal properties of the various grafted polymers are measured by gel permeation chromatography and differential scanning calorimetry, and the chemical modification of these materials is examined using infrared spectroscopy. The efficiency of the grafting reaction is estimated with thermogravimetric analysis. The degree of grafting is determined to range from 5% to 42%; this high degree of grafting is desirable to engineer an amine-responsive material. The response of the graft-polymers to amines is characterized using X-ray photoelectron spectroscopy, infrared spectroscopy, and differential scanning calorimetry. Changes in the chemical and thermal properties of the graft-polymers are observed after exposure to the vapors from a 400 ppm methylamine solution. In contrast to these changes, control samples of neat PLA do not undergo comparable changes in properties upon exposure to methylamine vapor. In addition, the PLA-g-SAh do not undergo changes in structure when exposed to vapors from deionized water without amines. This work presents potential opportunities for the development of real-time amine sensors.

Comparison between Different Extraction Methods for Determination of Primary Aromatic Amines in Food Simulant

The primary aromatic amines (PAAs) are food contaminants which may exist in packaged food. Polyurethane (PU) adhesives which are used in flexible packaging are the main source of PAAs. It is the unreacted diisocyanates which in fact migrate to foodstuff and then hydrolyze to PAAs. These PAAs include toluenediamines (TDAs) and methylenedianilines (MDAs), and the selected PAAs were 2,4-TDA, 2,6-TDA, 4,4'-MDA, 2,4'-MDA, and 2,2'-MDA. PAAs have genotoxic, carcinogenic, and allergenic effects. In this study, extraction methods were applied on a 3% acetic acid as food simulant which was spiked with the PAAs under study. Extraction methods were liquid-liquid extraction (LLE), dispersive liquid-liquid microextraction (DLLME), and solid-phase extraction (SPE) with C18 ec (octadecyl), HR-P (styrene/divinylbenzene), and SCX (strong cationic exchange) cartridges. Extracted samples were detected and analyzed by HPLC-UV. In comparison between methods, recovery rate of SCX cartridge showed the best adsorption, up to 91% for polar PAAs (TDAs and MDAs). The interested PAAs are polar and relatively soluble in water, so a cartridge with cationic exchange properties has the best absorption and consequently the best recoveries.

Transfer of primary aromatic amines from coloured paper napkins into four different food matrices and into cold water extracts

The aim of this study was to compare the transfer of primary aromatic amines (PAAs) from napkins into cold water extract (CWE) with transfer into four different food matrices. An HPLC-MS/MS multi-analyte method for quantification of 26 PAAs in CWE was validated and applied. In addition, the method was validated for seven different PAAs in four different food matrices (cucumber, rice, pickled gherkin and butter cookie) representing wet, dry, acidic and fatty food. The CWEs of 12 coloured napkin samples were analysed, and 3 napkins released more than 0.01 mg kg^-1 PAAs into the CWE. These three napkins were chosen for transfer testing with food samples. In total, seven different PAAs were quantified in the food samples. Results show that the transfer of the tested PAAs into the CWE is in most cases comparable to the transfer into the tested food samples. In some cases, the CWE overestimates transfer into food, except for the transfer of aniline into pickled gherkin, where the CWE underestimates transfer. Therefore, the CWE serves as an adequate and certainly not overestimating simulation of reality for the tested transfer of PAAs into the food samples.

Determination of primary aromatic amines in cold water extract of coloured paper napkin samples by liquid chromatography-tandem mass spectrometry

The aim of this study was the optimisation of a multi-analyte method for the analysis of primary aromatic amines (PAAs) from napkins in order to support official controls and food safety. We developed a UHPLC-MS/MS method for the simultaneous determination of 36 toxicologically relevant PAAs for paper and board. Good regression coefficients of the calibration curves in a range of 0.992-0.999 and reproducibilities in a range of 2.3-15% were obtained. Limits of detections (LODs) were in the range of 0.03-1.4 µg l(-1) and recoveries were in a range of 21-110% for all the amines. A total of 93 coloured paper napkin samples from different European countries were bought and extracted with water to determine the PAAs. The results showed that 42 of 93 samples contained at least one PAA. More than half of the detected PAAs are considered as toxic, carcinogenic or probably carcinogenic to humans by the International Agency for Research on Cancer (IARC), or are classified as such in the European Union legislation on chemicals. Summed concentrations of PAAs in seven samples were higher than 10 µg l(-1), the limit of summed PAA in the European Union plastic food contact material regulation. Also, eight PAAs, classified as Category 1A and 1B carcinogen in the European Union legislation of chemicals, were detected at concentrations higher than 2 µg l(-1), exceeding the limit proposed by the Federal Institute for Risk Assessment in Germany. Aniline (n = 14) was most frequently present in higher concentrations followed by o-toluidine, o-anisidine, 2,4-dimethylaniline and 4-aminoazobenzene. Red, orange, yellow and multicoloured paper napkins contained the highest concentrations of total PAAs (> 10 µg l(-1)). Although the European Union has not harmonised the legislation of paper and board materials and, thus, there is no specific migration limit for PAAs from paper napkins, the present study showed that coloured paper napkins can contain toxic and carcinogenic PAAs at concentrations that are relevant for monitoring.

Reliable liquid chromatography-mass spectrometry method for investigation of primary aromatic amines migration from food packaging and during industrial curing of multilayer plastic laminates

Primary aromatic amines (PAAs) can migrate from packaging into food from different sources such as polyurethanic adhesives used for the manufacture of multilayer films, which may contain residual aromatic isocyanates, or recycled paperboard, because of the presence of azo dyes in the printed paper massively used in the recycling process. In the present work, a reliable analytical method, exploiting a conventional high-performance liquid chromatography-(selected ion monitoring)-mass spectrometry system, for PAAs compliance assessment in food contact materials was developed as an effective alternative to the current standard spectrophotometric one, moving in this way from the screening to the accurate and selective quantitation perspective for the analysis of PAAs both in aqueous and acidic food simulants. The main validation parameters were verified achieving very satisfactory results in terms of linearity range, limit of detection (ranging from 0.1 to 1.0 µg kg(-1)) and quantitation (ranging from 0.1 to 3.6 µg kg(-1)), repeatability and accuracy. Suitability of the method was demonstrated for a wide range of commercial samples, chosen among different producers of the most common used food packaging plastic and paperboard categories and then analyzed to assess the risk related to PAAs migration. Finally, the method was also successfully exploited to monitor the evolution of potential PAAs migration during the industrial curing process of multilayer plastic laminates, prior to their release for delivery to the food industry end user.