The topic of the diploma thesis is fast separation of explosives by HPLC and development of miniaturized liquid chromatograph for application in a handheld explosives detection device. In this work the retention of some nitrated explosives and selectivity in reversed phase system as a function of mobile phase composition is studied while methanol, acetonitrile and acetone as an organic solvent is used. Best selectivity and good retention can be observed in methanol mobile phase. Acetonitrile and acetone are not suitable for fast isocratic separation of mixture containing pentaerythritol tetranitrate because of its strong retention. Efficiency and permeability of monolithic column (Chromolith CapRod RP-18e) and columns filled with superficially porous particles are compared (Kinetex 2,6 µm C-18, Poroshell 120 SB-C18). Monolithic column with satisfying efficiency and high column permeability is the most suitable solution for fast separation of explosives. Assuming use of explosives detection device in different conditions the separation was optimized on temperature 50 °C. Under these conditions the 35% v/v methanol gives good retention and selectivity. For very fast scan analysis of pentaerythritol tetranitrate or other nitroaromatics use of 70% v/v acetone mobile phase is suitable. Construction of miniaturized liquid chromatograph that enables preconcentration of explosives from aqueous solutions and fast separation in less than 1 minute is described. This concept will be incorporated into the handheld explosives detection device where the explosives vapor will be absorbed into the water and after the separation detected by chemiluminescence.

Essa dissertação de mestrado descreve o desenvolvimento de hardwares de colunas para cromatografia líquida capilar. O processo de desenvolvimentos desses dispositivos é descrito gradativamente e os pontos fortes e as limitações de cada modelo de hardware são discutidos. O melhor modelo de hardware desenvolvido apresentou produção simples, fácil conexão ao sistema cromatográfico e resistência a pressões superiores a 900 bar. Sucessivamente ao estabelecimento de um modelo de hardware apropriado, os efeitos dos materiais do hardware na eficiência das colunas foram avaliados. Poucos estudos relatam a influência do hardware nas separações em escala capilar, de forma que essa dissertação contribui para o preenchimento dessa lacuna. Capilares de aço inoxidável e sílica fundida e frits de aço inoxidável e fibra de vidro foram avaliados. Colunas com eficiências superiores a 100.000 pratos por metro foram produzidas. / This master\'s dissertation describes the development of hardware for capillary liquid chromatography columns. The development process of the devices is described gradually and the strengths and limitations of each model of hardware are discussed. The best-developed hardware model presented easy production, practice connection to the chromatographic system and resistance to pressures greater than 900 bar. After the establishment of an appropriate hardware model, the effects of hardware materials on the efficiency of the columns were evaluated. Few studies report the influence of the hardware on capillary scale separations; therefore, this dissertation contributes to fill this gap. Capillaries of stainless steel and fused silica and frits of stainless steel and glass fiber were evaluated. Columns with efficiencies greater than 100,000 plates per meter were produced.

Essa dissertação de mestrado descreve o desenvolvimento de hardwares de colunas para cromatografia líquida capilar. O processo de desenvolvimentos desses dispositivos é descrito gradativamente e os pontos fortes e as limitações de cada modelo de hardware são discutidos. O melhor modelo de hardware desenvolvido apresentou produção simples, fácil conexão ao sistema cromatográfico e resistência a pressões superiores a 900 bar. Sucessivamente ao estabelecimento de um modelo de hardware apropriado, os efeitos dos materiais do hardware na eficiência das colunas foram avaliados. Poucos estudos relatam a influência do hardware nas separações em escala capilar, de forma que essa dissertação contribui para o preenchimento dessa lacuna. Capilares de aço inoxidável e sílica fundida e frits de aço inoxidável e fibra de vidro foram avaliados. Colunas com eficiências superiores a 100.000 pratos por metro foram produzidas. / This master\'s dissertation describes the development of hardware for capillary liquid chromatography columns. The development process of the devices is described gradually and the strengths and limitations of each model of hardware are discussed. The best-developed hardware model presented easy production, practice connection to the chromatographic system and resistance to pressures greater than 900 bar. After the establishment of an appropriate hardware model, the effects of hardware materials on the efficiency of the columns were evaluated. Few studies report the influence of the hardware on capillary scale separations; therefore, this dissertation contributes to fill this gap. Capillaries of stainless steel and fused silica and frits of stainless steel and glass fiber were evaluated. Columns with efficiencies greater than 100,000 plates per meter were produced.