Um aparato para monitorar reações rápidas: um "stopped-flow" artesanal de baixo custo

Química Nova

Vagner Roberto Batistela¹  André Luiz Tessaro¹  Rafael R. Da S. Soares¹  Vagner Roberto De Souza¹  Noboru Hioka¹ 

[1] ,Universidade Estadual de Maringá Departamento de Química Maringá PR

关键词: stopped-flow;    kinetics;    fast reactions;   

DOI  :  10.1590/S0100-40422006000500034

来源: SciELO

【 摘 要 】

The modern stopped-flow reaction analyzer has shown high efficiency and flexibility, which provides outstanding sample economy with a dead-time of less than 1 ms. However the cost of the equipment imposes a serious restriction to many Brazilian scientists and teachers. In this work we describe the construction of a low-cost stopped-flow system coupled to a UV-Vis spectrophotometer. The performance of the system was checked by monitoring the kinetics of two reactions: the fading of phenolphthalein in aqueous alkaline solution and the chlorophyll a demetallation in acid medium. The apparatus showed reasonable efficiency with a dead-time of 0.3 to 0.5 s. The very good results obtained in these two illustrative processes show that the system is satisfactory for determining rate constants with mean reaction times ranging from seconds to minutes.

【 授权许可】

CC BY-NC   
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