Migration kinetics of primary aromatic amines from polyamide kitchenware: Easy and fast screening procedure using fluorescence

Chemometrics-assisted excitation-emission matrix fluorescence spectroscopy for real-time migration monitoring of multiple polycyclic aromatic hydrocarbons from plastic products to food simulants

Polycyclic aromatic hydrocarbons (PAHs), as a class of organic pollutants that have attracted much attention, are likely to be formed with the production and processing of plastic products, and they may migrate from contaminated plastic products to food, causing the risk of poisoning or cancer. In this study, migration tests were carried out on disposable plastic products for food contact, and a novel strategy that combines excitation-emission matrix (EEM) fluorescence spectroscopy with the advanced second-order calibration method based on the three-direction resection alternating trilinear decomposition (TDR-ATLD) algorithm was used to monitor the migration of three PAHs anthracene (ANT), pyrene (PYR), and phenanthrene (PHE) from the plastic products to food simulants in real-time. With the "second-order advantage", even if the fluorescence spectra of the target analytes overlapped seriously, and other unknown substances migrated from the plastic products to food simulants, accurate qualitative and quantitative results were still obtained by the proposed method. In the static system, the coefficient of determination (R2) of the three PAHs within the calibration range were all greater than 0.99, and the average spiked recoveries were 99.5-107.1%, with the standard deviation lower than 8.9%. The figures of merit (FOMs) and intra- or inter-day precision also showed good feasibility and reliability of the method. In the simulation study of the migration kinetic process, three PAHs can be quantified in real-time in complex matrix, then the related migration equations were established. The results indicate that the proposed method can be used for real-time migration quantitative monitoring of PAHs, providing a potential and available method for the study of the migration kinetics of hazardous substances from food contact materials to food or food simulants.

Procedure to explore a ternary mixture diagram to find the appropriate gradient profile in liquid chromatography with fluorescence detector. Application to determine four primary aromatic amines in napkins

The purpose of this work is to develop a tool to search for a gradient profile with ternary or binary mixtures in liquid chromatography, that can provide well-resolved chromatograms in the shortest time for multianalyte analysis. This approach is based exclusively on experimental data and does not require a retention time model of the compounds to be separated. The methodology has been applied for the quantification of four primary aromatic amines (PAAs) using HPLC with fluorescence detector (FLD). Aniline (ANL), 2,4-diaminotoluene (TDA), 4,4'-methylenedianiline (MDA) and 2-aminobiphenyl (ABP) have been selected since their importance in food contact materials (FCM). In order to achieve that, partial least squares (PLS) models have been fitted to relate CMP (control method parameters) and CQA (critical quality attributes). Specifically, PLS models have been fitted using 30 experiments for each one of the four CQA (resolution between peaks and total elution time), considering 33 predictor variables (the composition of the methanol and acetonitrile in the mobile phase and the time of each one of the 11 isocratic segments of the gradient). These models have been used to predict new candidate gradients, and then, some of those predictions (the ones with resolutions above 1.5, in absolute value, and final time lower than 20 min) have been experimentally validated. Detection capability of the method has been evaluated obtaining 1.8, 189.4, 28.8 and 3.0 µg L^-1 for ANL, TDA, MDA and ABP, respectively. Finally, the application of chemometric tools like PARAFAC2 allowed the accurate quantification of ANL, TDA, MDA and ABP in paper napkins in the presence of other interfering substances coextracted in the sample preparation process. ANL has been detected in the three napkins analysed in quantities between 33.5 and 619.3 µg L^-1, while TDA is present in only two napkins in quantities between 725.9 and 1908 µg L^-1. In every case, the amount of PAAs found, exceeded the migration limits established in European regulations.

Assessment of the migration of perfluorinated compounds and primary aromatic amines from PTFE-coated non-stick cookware marketed in Turkey

Two perfluorinated compounds (PFCs) and 17 different primary aromatic amines (PAAs) were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in migrants from 35 cookware samples marketed in Turkey. Among PFCs, only PFOA was identified in 6 samples. Only two components among PAAs, namely aniline (ANL) and 4,4'-methylenedianiline (4,4'-MDA), were detected in analyzed samples. Although aniline was detected in all samples, 4,4'-MDA was detected in only 4 samples. The effects of simulant volume, temperature, and repeated use on the release of these migrants from non-stick cookware were investigated. Three simulant volumes (200, 500, and 1000 mL) were used in migration tests. PFCs and PAAs were identified in simulants at 200 and 500 mL. The increase in the amount of simulant caused a decrease in the concentration of these migrants. The lowest migration values were observed in the samples at consecutive usage cycles. PFCs and PAAs exhibited the highest migration ability with increasing temperature.

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).

Integrated sample-pretreatment strategy for separation and enrichment of microplastics and primary aromatic amines in the migration of teabag

In this work, an integrated sample-pretreatment strategy for the separation and enrichment of microplastics and primary aromatic amines from the migration of teabag was developed. The migration solution of teabag was passed through a homemade device. The microplastics were firstly captured by a silver membrane, and then the primary aromatic amines were enriched by a solid-phase extraction column. The microplastics migrated from teabag were detected by attenuated total reflection-Fourier transform infrared spectrometer and Raman spectroscopy. The data showed the character, the number of particles, area ratio, and morphology of microplastics migrated from the teabag. Subsequently, after the enrichment procedure, a sensitive analytical method for primary aromatic amines was established followed by ultra-high performance liquid chromatography-tandem mass spectrometry. The method showed wide linear ranges with R² greater than 0.9915, low limits of detection (2-18 ng/L), and low limits of quantification (8-50 ng/L). The developed method was adopted to analyze microplastics and primary aromatic amines migrated from nylon and polyethylene terephthalate teabag under different temperatures and times. The integrated sample-pretreatment strategy displayed promising potentials in the one-step preparation of the microplastics and hazardous molecules in the sample of environment and food security.

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.

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.