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Abstract(s)
Os sensores em fibra ótica possuem inúmeras vantagens comparativamente a outras tecnologias de deteção. Após os anos 70, com o desenvolvimento de novas tecnologias de fabricação da fibra e o aperfeiçoamento das suas características, este tipo de sensores tem sido amplamente investigado, apresentando diversas aplicações. Por ser um meio bastante versátil para produção de tecnologias de deteção, a fibra ótica tem sido requerida para a monitorização de vários parâmetros físicos, como o índice de refração. O trabalho descrito nesta dissertação de mestrado está focado no desenvolvimento de sensores refratométricos em fibra ótica, de diferentes configurações e geometrias, para a monitorização do índice de refração no interior de um mesoreator de fluxo oscilatório (meso-OFR, do inglês meso oscillatory flow reactor), na cristalização em contínuo de princípios ativos (active pharmaceutical ingredients, APIs). A variação do índice de refração no interior do mesoreator permitirá, consequentemente, monitorizar a concentração ótica de APIs, mais especificamente, neste trabalho, do paracetamol. Quatro cabeças sensoras de diferentes configurações e com diferentes sensibilidades à variação da concentração de paracetamol foram desenvolvidas, nomeadamente, dois sensores refratométricos convencionais, cujas cabeças sensoras correspondem a fibras monomodo (SMF) e multimodo (MMF) clivadas, e dois sensores refratométricos avançados, uma microesfera oca e uma ponta com geometria cónica. Os resultados obtidos demonstraram que o sensor convencional MMF, de entre os desenvolvidos, seria o mais indicado para aplicação in situ. A sua sensibilidade, (-10.15 0.35) dB/(g/g), a sua simplicidade e o seu baixo custo de implementação são as principais vantagens deste sensor, em detrimento dos restantes desenvolvidos.
A variação da concentração de paracetamol ao longo do processo de cristalização foi monitorizada in situ, em regime “batch” e em regime contínuo (meso-OFR). A concordância de resultados obtida em ambos os regimes permitiu validar o sistema de interrogação portátil desenvolvido, assim como o potencial do sensor refratométrico MMF.Face à simplicidade de todo o sistema implementado, assim como ao seu baixo custo e mobilidade, reconhece-se que esta tecnologia, baseada em fibra ótica, é uma alternativa aos equipamentos analíticos utilizados na monitorização da concentração de APIs durante o processo de cristalização e a sua compatibilidade com a geometria meso-OFR poderá ser uma mais valia, no que diz respeito ao aproveitamento mais eficaz dos compostos. Desta forma, a aplicação do sensor refratométrico MMF à geometria meso-OFR, bastante explorada pela indústria, poderá otimizar ainda mais o desempenho deste sistema de cristalização.
Fiber optic sensors have numerous advantages compared to other detection technologies. After the seventy’s decade, with the development of new fiber manufacturing technologies and the improvement of its characteristics, this type of sensor has been extensively investigated, presenting several applications at the present time. Optical fiber has been required for the monitoring of various physical parameters, such as the refractive index, because it’s a very versatile way to produce detection technologies. The work described in this dissertation is focused on the development of refractive sensors in optical fiber of different configurations and geometries to monitor the refractive index inside of a meso oscillatory flow reactor (meso-OFR) in the continuous crystallization of active pharmaceutical ingredients (APIs). Therefore, the variation of the refractive index inside the mesoreator will allow monitoring the API's optical concentration, more specifically, in this work, the concentration of paracetamol. Four sensor heads of different configurations and with different sensitivities to the variation of paracetamol concentration were developed, namely, two conventional refractometric sensors, whose sensor heads correspond to cleaved single mode (SMF) and multimode (MMF) fibers, and two advanced refractometric sensors, one hollow microsphere and a tip with conical geometry. The results obtained demonstrated that the conventional MMF sensor would be the most suitable for in situ application. Its sensitivity (-10.15 0.35) dB/(g/g), its simplicity and its low cost of implementation are the main advantages of this sensor compared with the others. The variation of paracetamol concentration throughout the crystallization process of paracetamol was monitored in situ, in “batch” and continuous regime (meso-OFR). The agreement of results obtained in both regimes allowed to validate the developed portable interrogation system, as well as the potential of MMF refractometer sensor. The simplicity of the whole system implemented, as well as its low coast and mobility, allow to be recognized that this technology, based on fiber optics, is an alternative to the analytical equipment used to monitor the concentration of APIs during the crystallization process and their compatibility with meso-OFR may be of added value for the most effective use of compounds. In this way, the application of MMF refractometric sensor to the to the widely explored meso-OFR geometry can further optimize the performance of this crystallization system.
Fiber optic sensors have numerous advantages compared to other detection technologies. After the seventy’s decade, with the development of new fiber manufacturing technologies and the improvement of its characteristics, this type of sensor has been extensively investigated, presenting several applications at the present time. Optical fiber has been required for the monitoring of various physical parameters, such as the refractive index, because it’s a very versatile way to produce detection technologies. The work described in this dissertation is focused on the development of refractive sensors in optical fiber of different configurations and geometries to monitor the refractive index inside of a meso oscillatory flow reactor (meso-OFR) in the continuous crystallization of active pharmaceutical ingredients (APIs). Therefore, the variation of the refractive index inside the mesoreator will allow monitoring the API's optical concentration, more specifically, in this work, the concentration of paracetamol. Four sensor heads of different configurations and with different sensitivities to the variation of paracetamol concentration were developed, namely, two conventional refractometric sensors, whose sensor heads correspond to cleaved single mode (SMF) and multimode (MMF) fibers, and two advanced refractometric sensors, one hollow microsphere and a tip with conical geometry. The results obtained demonstrated that the conventional MMF sensor would be the most suitable for in situ application. Its sensitivity (-10.15 0.35) dB/(g/g), its simplicity and its low cost of implementation are the main advantages of this sensor compared with the others. The variation of paracetamol concentration throughout the crystallization process of paracetamol was monitored in situ, in “batch” and continuous regime (meso-OFR). The agreement of results obtained in both regimes allowed to validate the developed portable interrogation system, as well as the potential of MMF refractometer sensor. The simplicity of the whole system implemented, as well as its low coast and mobility, allow to be recognized that this technology, based on fiber optics, is an alternative to the analytical equipment used to monitor the concentration of APIs during the crystallization process and their compatibility with meso-OFR may be of added value for the most effective use of compounds. In this way, the application of MMF refractometric sensor to the to the widely explored meso-OFR geometry can further optimize the performance of this crystallization system.
Description
Keywords
Sensor refratométrico Mesoreator de fluxo oscilatório Cristalização Princípios ativos Refractometric sensor Paracetamol Meso oscillatory flow reactor Crystallization Active pharmaceutical ingredients