Analysis of polycyclic aromatic hydrocarbons in fish: optimisation and validation of microwave-assisted extraction

An accurate and sensitive method for determination of 18 polycyclic aromatic hydrocarbons (PAHs) (16 PAHs considered by USEPA as priority pollutants, dibenzo[a,l]pyrene and benzo[j]fluoranthene) in fish samples was validated. Analysis was performed by microwave-assisted extraction and liquid chromatography with photodiode array and fluorescence detection. Response surface methodology was used to find the optimal extraction parameters. Validation of the overall methodology was performed by spiking assays at four levels and using SRM 2977. Quantification limits ranging from 0.15–27.16 ng/g wet weight were obtained. The established method was applied in edible tissues of three commonly consumed and commercially valuable fish species (sardine, chub mackerel and horse mackerel) originated from Atlantic Ocean. Variable levels of naphthalene (1.03–2.95 ng/g wet weight), fluorene (0.34–1.09 ng/g wet weight) and phenanthrene (0.34–3.54 ng/g wet weight) were detected in the analysed samples. None of the samples contained detectable amounts of benzo[a]pyrene, the marker used for evaluating the occurrence and carcinogenic effects of PAHs in food.

Analysis of polycyclic aromatic hydrocarbons in fish: evaluation of a quick, easy, cheap, effective, rugged, and safe extraction method

QuEChERS method was evaluated for extraction of 16 PAHs from fish samples. For a selective measurement of the compounds, extracts were analysed by LC with fluorescence detection. The overall analytical procedure was validated by systematic recovery experiments at three levels and by using the standard reference material SRM 2977 (mussel tissue). The targeted contaminants, except naphthalene and acenaphthene, were successfully extracted from SRM 2977 with recoveries ranging from 63.5–110.0% with variation coefficients not exceeding 8%. The optimum QuEChERS conditions were the following: 5 g of homogenised fish sample, 10 mL of ACN, agitation performed by vortex during 3 min. Quantification limits ranging from 0.12– 1.90 ng/g wet weight (0.30–4.70 µg/L) were obtained. The optimized methodology was applied to assess the safety concerning PAHs contents of horse mackerel (Trachurus trachurus), chub mackerel (Scomber japonicus), sardine (Sardina pilchardus) and farmed seabass (Dicentrarchus labrax). Although benzo(a)pyrene, the marker used for evaluating the carcinogenic risk of PAHs in food, was not detected in the analysed samples (89 individuals corresponding to 27 homogenized samples), the overall mean concentration ranged from 2.52 l 1.20 ng/g in horse mackerel to 14.6 ± 2.8 ng/ g in farmed seabass. Significant differences were found between the mean PAHs concentrations of the four groups.

Secretaria on-line from ISCAP

Like many other higher educat ion schools, ISCAP`s population has grown at a rate of almost 100% in the end of the twentieth century. Its administrative structures were reinforced, but it was not in the same proportion. Face to face with the inability to resolve the problem, the administration decided to implement a computer based system, available in the Internet. In a first stage, in 1997, the system was implemented as a services support. The next stage, in 1999, proposes to increase student services quality. A project that aims to bring student services available on the Internet begins to be developed.

Aplicação das tecnologias de informação e comunicação como estratégia para a retenção de aunos

Este artigo aborda a aplicação das Tecnologias de Informação e Comunicação como estratégias de boas práticas que conduzem à retenção e captura de alunos do ensino superior. É baseado num estudo de caso de oito anos, de utilização de um completo sistema de informação. Este sistema, além de constituir um ERP, de suporte às actividades de gestão académica, dispõe ainda de uma forte componente de SRM que confere suporte às actividades administrativas e lectivas. É descrito em que medida o sistema apresentado facilita a interacção e comunicação entre os membros da comunidade académica, recorrendo à internet, com serviços disponíveis na Web complementando-os com correio electrónico, SMS e CTI. Através de uma percepção, sustentada por análise empírica e por resultados de inquéritos, demonstra-se como este tipo de boas práticas pode elevar o nível de satisfação da comunidade. Muito em particular, é possível combater o insucesso escolar, evitar que alunos abandonem os seus cursos antes do seu término e que os recomendem a potenciais alunos. Em complemento, este tipo de estratégia permite ainda fortes economias na gestão da instituição, elevando o seu valor. Como trabalho futuro, é apresentada a nova fase do projecto que envereda pela aplicação de Business Intelligence para optimização do processo de gestão, tornando-o pró-activo. Também é apresentada a visão tecnológica que orienta os novos desenvolvimentos, para uma arquitectura baseada em serviços Web e linguagens de definição processual.

Technology strategies in the process of student retention and efficiency of academic management

This article discusses the application of Information and Communication Technologies and strategies for best practices in order to capture and maintain faculty students' attention. It is based on a case study of ten years, using a complete information system. This system, in addition to be considered an ERP, to support the activities of academic management, also has a strong component of SRM that provides support to academic and administrative activities. It describes the extent to which the presented system facilitates the interaction and communication between members of the academic community, using the Internet, with services available on the Web complementing them with email, SMS and CTI. Through a perception, backed by empirical analysis and results of investigations, it demonstrates how this type of practice may raise the level of satisfaction of the community. In particular, it is possible to combat failure at school, avoid that students leave their course before its completion and also that they recommend them to potential students. In addition, such a strategy also allows strong economies in the management of the institution, increasing its value. As future work, we present the new phase of the project towards implementation of Business Intelligence to optimize the management process, making it proactive. The technological vision that guides new developments to a construction based on Web services and procedural languages is also presented.