Determination of azide in biological fluids by use of electron paramagnetic resonance

A simple and sensitive method has been developed for the determination of azide ion (N3 - ) in biological fluids and beverages. The procedure was based on the formation of a ternary complex Cu(N3)2(4-methylpyridine)x in benzene, followed by its detection by electron paramagnetic resonance. The complex in benzene showed a characteristic four-peak hyperfine structure with a g-value of 2.115 at room temperature. Cu2+ reacted with N3 - most strongly among common metals found in biological fluids. Several anions and metal ions in biological fluids did not interfere with the determination of N3 - in the presence of large amounts of Cu2+ and oxidants. In the present method, N3 - at the concentration from 5 μM to 2 mM in 100 μl solution could be determined with the detection limit of 20 ng. The recoveries were more than 95 % for N3 - added to 100 μl of blood, urine, milk and beverages at 200 μM. Our method is recommendable because it takes less than 10 min to determine N3 - and the produced complex is quite stable

Diagnóstico jurídico sobre el decomiso y manejo postdecomiso de fauna silvestre en el departamento del Chocó

En este artículo se presenta un estudio de carácter descriptivo sobre los decomisos y el manejo postdecomiso de fauna silvestre en el departamento del Chocó utilizado como corredor para el tráfico y comercialización ilegal; se analizan, a partir del marco jurídico colombiano, la definición de fauna silvestre, decomiso y sus consecuencias jurídicas. Entre el 2005 y marzo del 2011 se realizaron en el Chocó 904 decomisos: 316 aves, 321 reptiles y 264 de mamíferos, 1 anfibio, 1 arácnido y 1 pez. La tendencia ha sido el aumento. La principal opción de disposición de fauna decomisada es la Liberación. Se han impuesto solamente sanciones de tipo administrativo sin reporte en el Registro Único de Infractores Ambientales y no se ha adelantado ninguna investigación de tipo pena

Biodegradable and compostable alternatives to conventional plastics

This article is available open access through the publisher’s website at the link below. Copyright @ 2009 The Royal Society.Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.EPSR