Evaluation of a screening method for classifying virgin and recycled paper and board samples

This paper deals with the study of volatile compounds released by recycled paper and board. The aim of the study was to demonstrate the feasibility of headspace procedure coupled to gas chromatography/mass spectrometry (GC/MS) applied to complex paper‐based samples together with a chemometric procedure as a powerful method for screening potential volatile contaminants released by the recycled and virgin paper samples. Using this procedure, the identification of virgin or recycled paper could be achieved based on the identification on specific markers of the recycled pulp. Fifteen different samples within virgin and recycled paper were studied. After equilibration, the vapour phase of the samples was analysed by automatic headspace coupled online to GC/MS. The analytical approach for volatile compounds, their identification and the selection of some compounds as markers for recycled pulp are shown and discussed. A discriminate analysis applied to the set of results obtained allows classification of the samples into four different groups according to the content of recycled pulp (0, 10–30 and > 80% of recycled pulp), the surface treatment of the paper (no surface treatment, clay coating and plastic coating), the grammage (from < 100 to > 300 g/m²) and the sample thickness (from < 300 to > 600 µm). The matrix effect on the volatilization of some compounds from the paper samples and the analytical behaviour are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Multicomponent recycled plastics: considerations about their use in food contact applications.

Two multicomponent post-use recycled plastics named as NPP40A3 (formulated with 85% HDPE and 15% of a PP-PS-PVC mixture) and NPP40A6 (formulated with 80% NPP40A3, 10% ABS and 10% HIPS), both of them with 3.1% of plasticizer and 0.6% of stabilizer to obtain a better final product, have been analysed. Plastics were extracted both with dichloromethane and methylbenzene, and analysed by HPLC and GC-MS to identify the maximum possible number of compounds. Major additives quantified were di(ethylhexyl)phthalate (3.262% and 2.955% respectively) and Irganox 1010 (0.473% and 0.498% respectively). Several degradation compounds have been detected. In order to check if these plastics could be used in food contact applications, global and specific migration tests have been applied. The results obtained are discussed.     

Fabrication of DNA-magnetite hybrid nanofibers for water detoxification

DNA-magnetite hybrid nanofibers were fabricated by electrospinning a spin dope consisting of oleic acid coated magnetite nanoparticles and DNA-CTMA in ethanol/chloroform mixed solvent. The fabricated nanofibers exhibit superparamagnetic behaviour owing to embedded magnetite nanoparticles. It is demonstrated that these nanofibers can be used as effective detoxification materials in aqueous media as a combined result of DNA's affinity to both organic and inorganic toxicants, high surface area of the nanofibers and the fast and easy separation due to magnetite nanoparticles under external magnetic field. In addition to detoxification, these novel hybrid nanofibers have potential applications in many technological areas such as catalysis and drug delivery.     

Wärmetransformatoren für die Chemische Industrie aus der Sicht des Anwenders

Absorption heat transformers for the chemical industry as seen from a user's point of view. Absorption heat transformers can transfer waste heat, that could not hitherto be reused, to a higher temperature level. This is of special interest for the chemical industry, where there is both waste heat available at temperatures below 100°C and a demand for heat at 120 to 150°C. Though absorption heat transformers are able to recycle only a part of the total waste heat, they only need a negligible amount of additional, expensive exergy. The present status of development and advantages and disadvantages of the concept are discussed from a user's point of view. In view of the present low price of energy, special attention is given to economic considerations.     

On‐Substrate Preparation of an Electroactive Conjugated Polyazomethine from Solution‐Processable Monomers and its Application in Electrochromic Devices

An electroactive polyazomethine is prepared from a solution processable 2,5‐diaminothiophene derivative and 4,4′‐triphenylamine dialdehyde by spray‐coating the monomers on substrates, including indium tin oxide (ITO) coated glass and native glass slides. The conjugated polymer was rapidly formed in situ by heating the substrates at 120 °C for 30 min in an acid saturated atmosphere. The resulting immobilized polymer is easily purified by rinsing the substrate with dichloromethane. The on‐substrate polymerization is tolerant towards large stoichiometry imbalances of the comonomers, unlike solution step‐growth polymerization. The resulting polyazomethine is electroactive and it can be switched reversibly between its neutral and oxidized states both electrochemically and chemically without degradation. A transmissive electrochromic device is fabricated from the immobilized polyazomethine on an ITO electrode. The resulting device is successfully cycled between its oxidized (dark blue) and neutral (cyan/light green) states with applied biases of +3.2 and ‐1.5 V under ambient conditions without significant color fatigue or polymer degradation. The coloration efficiency of the oxidized state at 690 nm is 102 cm² C^?1.     

Reducing Oxidation of Foods Through Antioxidant Active Packaging Based on Ethyl Vinyl Alcohol and Natural Flavonoids

The development of antioxidant active packaging systems is attracting considerable attention as one of the preferred emerging technologies for reducing the incidence of lipid peroxidation. This work presents the use of ethylene vinyl alcohol copolymer films containing two natural flavonoids, catechin and quercetin, to reduce the oxidation of food. In a series of experiments, these materials showed their ability to reduce the presence of hydroxyl radicals in the package headspace. Packaging fried peanuts in bags manufactured with these active films resulted in a large reduction in the presence of hexanal, a compound produced during peroxidation of the unsaturated fat in peanuts. The results indicated that the materials actively reduced the presence of radical oxidative species although the antioxidants are not released into the food. On exposing sunflower oil to the films, the peroxide values obtained showed that the films actively protected the oil; because of the higher solubility of quercetin in this food product as well as the higher antioxidant capacity, the samples containing this flavonoid were more efficient. Industrial relevance: Active packaging is receiving considerable attention as an emerging technology that can be used to improve the quality and the stability of food, reducing the direct addition of chemicals and the need for changes in formulation. The results of this study show that it is possible to reduce food oxidation without adding antioxidants to the food. The films obtained can be used to protect any type of food, including dry or fatty products. Copyright © 2012 John Wiley & Sons, Ltd.     

Use of lichens as pollution biomonitors in remote areas: comparison of PAhs extracted from lichens and atmospheric particles sampled in and around the Somport tunnel (Pyrenees)

Lichens of the species Parmelia sulcata were collected from sites on both sides of the Somport tunnel (which links France and Spain) and atmospheric particles were collected by air samplers installed within and on either side of the tunnel. Polycyclic aromatic hydrocarbons (PAHs) in the lichen and particle samples were then extracted, identified, quantified, and compared to evaluate the potential utility of lichens as pollution biomonitors in remote areas. The origin of the PAHs was also assessed using the Phe/Ant, Flu/Pyr, Ant/Ant+Phe, Flu/Flu+Pyr, and BaA/BaA+Chr concentration ratios. The total concentration of 16 priority PAHs ranged from 6.79 to 23.3 microg/g in particles outside the tunnel, from 18.3 to 265.2 microg/g in particles inside the tunnel, and from 0.91 to 1.92 microg/g in the lichen samples. The PAH ratios found in the lichens and particulate matter indicate that they were of pyrogenic origin and that road traffic was a major contributor. Results from the lichen samples suggest that they may be excellent biomonitors of pollution in remote areas.