Solid-phase microextraction based sampling techniques for the analysis of volatile organic compounds in the atmosphere

Volatile organic compounds (VOCs) comprise a large diversity of species that are emitted into the atmosphere from both biogenic and anthropogenic sources. These species play a key role in atmospheric photochemistry, due to their high reactivity with atmospheric oxidants, and in the formation and growth of secondary organic aerosols. The trace levels usually found in ambient air and the enormous heterogeneity of VOC sources and emissions around the Earth call for the development of novel analytical methodologies and portable devices, which provide reduced analytical steps and allow the measurement of these compounds at virtually any spatial location. The main goal of this doctoral thesis was to develop further and apply solid-phase microextraction (SPME) based analytical methods for the sampling and analysis of VOCs in the atmosphere. The SPME techniques used included conventional SPME fibers, needle trap microextraction (NTME) devices and a novel SPME Arrow system. Portable gas chromatography-mass spectrometry (GC-MS) was employed for the fast on-site measurement of atmospheric volatiles. Field measurements were performed at the Station for Measuring Ecosystem-Atmosphere Relations (SMEAR II) in Hyytiälä, Finland. Dynamic SPME collection combined with portable GC-MS allowed the rapid on-site measurement of the most abundant compounds present in the sampling site atmosphere with minimal analytical steps. The potential of NTME and portable GC-MS for the field measurement of biogenic and anthropogenic organic volatiles was also demonstrated, and the method developed was applied to clarify the effect of snow pack on the concentration of biogenic volatile organic compounds (BVOCs) in the air. SPME and portable GC-MS were used for the characterization of BVOCs emitted from chambers installed at the forest soil. A novel SPME Arrow system was also successfully characterized and employed for the sampling of atmospheric VOCs. The results demonstrated the great potential and versatility of SPME-based sampling techniques combined with portable GC-MS for the rapid on-site sampling and analysis of VOCs in the atmosphere.not availabl

Estudo da notoriedade das iniciativas de RSE junto dos consumidores : o caso da OPTIMUS, TMN e VODAFONE

Mestrado em MarketingA Responsabilidade Social Empresarial (RSE) tem despertado, cada vez mais, o interesse da investigação de marketing, nomeadamente no que diz respeito à relação entre a RSE e o consumidor. Vários estudos avaliaram o impacto da RSE no comportamento do consumidor, tendo concluído que as suas atitudes são influenciadas pelas iniciativas de RSE. No entanto, alguns autores (exemplos: Maignan, 2001:58; e Mohr et al., 2001:48) teceram críticas a esses estudos pelo facto de terem assumido que a notoriedade das iniciativas de RSE existia, e sugeriram o desenvolvimento de estudos que determinassem o nível de notoriedade destas iniciativas junto dos consumidores. O presente estudo tem como objetivo responder a esta recomendação, examinando a notoriedade dos projetos sociais das marcas Optimus, TMN e Vodafone junto dos consumidores. Os resultados mostraram que os consumidores têm um fraco conhecimento desses projetos, em especial no caso da Optimus. Além disso, verificou-se uma clara dificuldade em associar os diversos projetos aos operadores e em descrever os respetivos objetivos, o que vem reforçar a necessidade de melhorar a efetividade da comunicação. De facto, tal como Mohr et al. (2001:48) sugerem, se os consumidores não têm conhecimento das iniciativas de RSE, os respetivos benefícios que foram estudados na literatura são apenas relevantes do ponto de vista teórico, tendo pouca repercussão prática nas empresas.Corporate Social Responsibility (CSR) has attracted, increasingly, the marketing research, particularly with regard to the relationship between CSR and the consumer. Several studies have evaluated the impact of CSR on consumer behavior and concluded that their attitudes are influenced by CSR initiatives. However, some authors (eg Maignan, 2001:58; and Mohr et al., 2001:48) have criticized these studies because they have previously assumed that the awareness of CSR initiatives existed. As such, the authors suggested the development of studies to determine the level of awareness among consumers. This study aims to answer this recommendation by examining the consumer awareness of the social projects of Optimus, TMN and Vodafone. The results showed that the awareness is low, especially in the case of Optimus. In addition, there was a clear difficulty in linking the various projects to operators and describe the respective goals, which reinforces the need to improve communication effectiveness. In fact, as Mohr et al. (2001:48) suggest, if consumers are not aware of CSR initiatives, the CSR benefits that have been studied in the literature are only relevant in theory, having little effect on business