Migration is a known phenomenon defined as the partitioning of certain chemical compounds from plastic food packaging into food and has been intensely investigated in recent years. Due to outstanding chemical and physical properties plastics are used in many fields. Polypropylene and polyethylene are extensively used polymers because of their chemical resistance, high tensile strength and low density. To improve the properties of the plastics, additives such as plasticizers, stabilizers, antioxidants, lubricants, pigments and others are required to be added. However, they can migrate from the plastics into the food and contaminate it during production or storage. Therefore, the aim of this study was to investigate commercial polypropylene and polyethylene packages to determine what most often used additives and degradation products of the food packages can migrate to food. After the initial identification of plastics by Fourier-transform infrared spectrometry, the determination of cadmium, chromium, lead and mercury was carried out by atomic absorption spectrophotometry. To evaluate possible volatile and semi-volatile organic compounds thermal desorption gas chromatography coupled with mass spectrometry was used. The results revealing the presence of different potential organic compounds and metals emitted during the degradation process of different types of food contact materials are discussed.
The wet chemistry route has been developed to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, (HA)) thin films on a silicon substrate using the novel low-temperature sol-gel and dissolution-precipitation approach. The calcium carbonate thin films on the silicon substrate were obtained by spin-coating technique when substrates were repeatedly coated with 10, 20 and 30 layers of sol-gel solution. The composites formed of crystalline and amorphous CaCO3 were obtained by calcination of the coatings for different time at 600°C. A dissolution-precipitation procedure was used for the preparation of calcium hydroxyapatite thin films on silicon substrate at 80°C. The obtained synthesis products were characterised by X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM) and Raman spectroscopy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.