Effect of amines in the release of bisphenol A from polycarbonate baby bottles

The key block for the production of polycarbonate (PC) is bisphenol A (BPA). Recent studies have proven that this monomer is able to migrate from PC baby bottles into food simulants and, although this is a polemical subject, numerous investigations indicate that BPA may have an effect on the human health. For these reasons, BPA safety regarding human exposure has recently become an alarming issue.Amines are a class of chemicals which are present in foodstuffs, such as milk. For this reason PC baby bottles, while being used, are continuously in contact with several amines, some of which are able to cause PC aminolysis, resulting in the release of BPA.In this work, 16 substances (14 with amine groups and 2 with amide groups) were tested in order to verify if they were able to increase BPA release by increasing PC depolymerization. High-performance liquid chromatography (HPLC) with fluorescence detection (FLD) and gas chromatography coupled to mass spectrometry (GC–MS) were used to quantify and identify the BPA, respectively. Although most of the substances tested did not increase the release of BPA from PC, some of them had a significant effect and high levels of this monomer were measured in the solutions. Of all of the amines tested that originating the worst case of BPA release was 1,4-diaminobutane. Also known as putrescine, 1,4-diaminobutane is a biogenic amine that results from protein degradation and it may be present in milk. In this case, BPA concentration in the solution was more than 5000 times the level found in the control sample.     

Development of a multimethod for the determination of photoinitiators in beverage packaging

ABSTRACT:  Photoinitiators are ink components used in the printing of food packaging. The aim of the present study was to develop a multimethod for the analysis of photoinitiators in paperboard packages and commercial beverage packages. The proposed method is simple and fairly rapid. Extraction is carried out with acetonitrile. A reverse-phase high performance liquid chromatography (HPLC) method with UV detection was developed to quantify the 6 selected photoionitiators. Total HPLC time analysis was 30 min and the flow-rate was 1 mL/min. Method validation parameters such as linearity and detection limit are reported. Recovery of all photoinitiators (at 1 mg/kg) from orange juice was satisfactory (mean = 88.4%; ranging from 84.6% to 93.4%). Recovery of benzophenone and Irgacure 651 was good (ranging from 85.2% to 98.1% and 86.1% to 92.2%, respectively) at the 4 concentrations studied (0.1, 0.2, 0.5, and 1 mg/kg). Commercial beverage packages were analyzed and when photoinitiators were detected, the beverages were also analyzed.     

Validation of a liquid chromatography–mass spectrometry method for determining the migration of primary aromatic amines from cooking utensils and its application to actual samples

Many cooking utensils are made of nylon, a material that may incorporate azodyes and where primary aromatic amines (PAAs) are the starting substances. Moreover, aromatic amines may also be present as technical impurities. Another source of PAAs could be aromatic isocyanates used as monomers in the production of polyurethanes. The aim of this work was to validate a simple LC–MS/MS method for the determination of eight primary aromatic amines (m-phenylenediamine, 2,6- and 2,4-toluenediamine, 1,5-diaminonaphthalene, aniline, 4,4′-diaminonaphenylether, 4,4′-methylenedianiline and 3,3′-dimethylbenzidine) in the aqueous food simulant 3% acetic acid (w/v). The detection limits calculated were adequate with respect to present legislation. The method was validated at four concentration levels (2, 5 10 and 20 µg kg^?1). Global internal reproducibility was in the range 5.6–21.4% (RSD_R) depending on the compound and concentration. Mean recoveries for all levels varied between 89 and 100%, depending on the amine. A total of 39 samples of cooking utensils were analyzed using the described method and the results obtained after the third migration test were not compliant in approximately half of the samples.     

Correlation of foodstuffs with ethanol–water mixtures with regard to the solubility of migrants from food contact materials

Today most foods are available in a packed form. During storage, the migration of chemical substances from food packaging materials into food may occur and may therefore be a potential source of consumer exposure. To protect the consumer, standard migration tests are laid down in Regulation (EU) No. 10/2011. When using those migration tests and applying additional conservative conventions, estimated exposure is linked with large uncertainties including a certain margin of safety. Thus the research project FACET was initiated within the 7th Framework Programme of the European Commission with the aim of developing a probabilistic migration modelling framework which allows one (1) to calculate migration into foods under real conditions of use; and (2) to deliver realistic concentration estimates for consumer exposure modelling for complex packaging materials (including multi-material multilayer structures). The aim was to carry out within the framework of the FACET project a comprehensive systematic study on the solubility behaviour of foodstuffs for potentially migrating organic chemicals. Therefore a rapid and convenient method was established to obtain partition coefficients between polymer and food, K_P/F. With this method approximately 700 time-dependent kinetic experiments from spiked polyethylene films were performed using model migrants, foods and ethanol–water mixtures. The partition coefficients of migrants between polymer and food (K_P/F) were compared with those obtained using ethanol–water mixtures (K_P/F’s) to investigate whether an allocation of food groups with common migration behaviour to certain ethanol–water mixtures could be made. These studies have confirmed that the solubility of a migrant is mainly dependent on the fat content in the food and on the ethanol concentration of ethanol–water mixtures. Therefore dissolution properties of generic food groups for migrants can be assigned to those of ethanol–water mixtures. All foodstuffs (including dry foods) when allocated to FACET model food group codes can be classified into a reduced number of food categories each represented by a corresponding ethanol–water equivalency.     

Mass transport studies of different additives in polyamide and exfoliated nanocomposite polyamide films for food industry

The development of new food packaging films through the incorporation of nanoparticles, and the effect of the nanoparticles on the process of migration of the substances used in manufacturing the new films is expected to lead to an improvement in the shelf life of food and thus, consumer safety and health. In recent years, attention has focused on nanocomposites because these compounds often exhibit unexpected hybrid properties derived from synergistic reactions between nanoparticles and the polymeric matrix. The exfoliation of nanoclays in polyamide film provides a film with better barrier properties than that obtained through the intercalation of nanoclays. Migration of chemicals from food packaging into food may produce potential adverse health effects because of exposure to toxic compounds. The present study addressed the migration of caprolactam, 5‐Chloro‐2‐(2,4‐dichlorophenoxy)phenol (triclosan) and trans,trans‐1,4‐diphenyl‐1,3‐butadiene (DPBD) from polyamide and polyamide‐nanoclays to different types of food simulants. The values for limit of detection (LOD) obtained for caprolactam, triclosan and DPBD was 0.5 mg/L, 0.02 mg/L and 0.01 mg/L, respectively. Furthermore, instrumental precision was evaluated through repeatability injections, resulting in relative standard deviations lower than 3.08%. Diffusion coefficients were calculated according to a mathematical model based on Fick's Second Law, and the results were discussed in terms of the parameters that may have the greatest effect on migration. The presence of polymer nanoparticles was found to slow down the rate of migration of substances from the matrix polymer into the food up to six times. Copyright © 2009 John Wiley & Sons, Ltd.     

Chromatographic Methods for the Determination of Polyfunctional Amines and Related Compounds Used as Monomers and Additives in Food Packaging Materials: A State‐of‐the‐Art Review

Abstract: Polyfunctional amines are a group of substances commonly used as additives or monomers in food‐contact materials. These substances can migrate into foodstuffs and, consequently, may be potentially dangerous for human health. Due to their different chemical structures and physicochemical properties there does not exist a standard method to analyze polyfunctional amines. This review aims to provide an update on the chromatographic methods used for the determination of polyfunctional amines that are commonly used in the manufacture of food packaging materials. Detailed information regarding chromatographic conditions (mobile phases, chromatographic columns, detection systems, and so on) is provided. Moreover, chemical structures and physicochemical properties of the substances studied are also presented.     

Migration of ε-caprolactam from nylon cooking utensils: validation of a liquid chromatography-ultraviolet detection method

A large amount of modern cooking utensils are made of nylon. This is the generic name of polyamides that are polymers having characteristic amide linkages. Caprolactam is the monomer used in the synthesis of nylon 6. This work presents the validation of an LC-UV method for the determination of caprolactam in the aqueous food simulant 3% acetic acid (w/v) employing capryllactam as internal standard. LC–MS/MS was the confirmation technique. The obtained detection and quantification limits were satisfactory regarding caprolactam specific migration limit; these were 0.6 and 2 mg kg⁻¹, respectively. The working range was 2–30 mg kg⁻¹ and the correlation coefficients (r) were in all cases at least 0.999. The intra-day repeatability was between 2.5 and 4.8% depending on the validation level. The global mean recovery was 100.6% with a RSD (%) of 5.0%. Different nylon cooking utensils were analyzed for the migration of caprolactam in the food simulant acetic acid 3% p/v. Conditions used were repeated exposure to the simulant for 2 h at 100 °C, and the results obtained after the third exposure were in compliance regarding Directive 2002/72/EC. With the aim of identifying the polymer used in these utensils, IR spectra were also obtained for all samples.     

Evolution of engineering change and repair technology in highperformance multichip modules at IBM

In multichip modules (MCMs), engineering changes (EC) are required for both repair of defective chip to chip connections within the module, as well as modification of electrical connections for module performance optimization. With the recent use of complementary metal-oxide-semiconductor (CMOS) chips in IBM's latest generation of mainframe machines, EC design has been modified to accommodate chips with a much higher number of signal I/Os. Using the previous design methodology of connecting each signal C4 to an EC pad, a large area of the top surface of the module would be required for EC features. This would force increased chip-to-chip wiring length and impact module performance. In addition, larger size MCMs would be required, driving up cost. The new EC approach utilizes top surface thin film wiring in the X and Y directions, which is not pre-connected to any signal C4 pads. The approach used to make desired EC connections is described. New processes were developed to make micro-connections to customize an EC connection, CMOS based MCMs have more than 5× the signal I/Os per chip compared to bipolar devices. As a result of the evolution in EC technology, CMOS chip based MCMs have been successfully designed, built, tested and debugged quickly. They are being used in IBM's latest generation mainframe machines     

Typical diffusion behaviour in packaging polymers - application to functional barriers

When plastics are collected for recycling, possibly contaminated articles might be recycled into food packaging, and thus the contaminants might subsequently migrate into the food. Multilayer functional barriers may be used to delay and to reduce such migration. The contribution of the work reported here is to establish reference values (at 40°C) of diffusion coefficients and of activation energies to predict the functional barrier efficiency of a broad range of polymers (polyolefins, polystyrene, polyamide, PVC, PET, PVDC, [ethylene vinyl alcohol copolymer], polyacrylonitrile and [ethylene vinyl acetate copolymer]). Diffusion coefficients (D) and activation energies (Ea) were measured and were compiled together with literature data. This allowed identification of new trends for the log D = f(molecular weight) relationships. The slopes were a function of the barrier efficiency of the polymer and temperature. The apparent activation energy of diffusion displayed two domains of variation with molecular weight (M). For low M (gases), there was little variation of Ea. Focusing on larger molecules, high barrier polymers displayed a larger dependence of Ea with M. The apparent activation energy decreased with T. These results suggest a discontinuity between rubbery and glassy polymers.