Optical sensors and instrumentations for determination of contaminants in water / Sensores opticos e instrumentação para determinação de contaminantes em aguas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This work describes the development of optical sensors for determination of benzene, toluene, ethylbenzene and xylenes (BTEX) and metal ions in water. For the determination of BTEX, monoliths of polydimethylsiloxane (PDMS) were inserted into a bottle filled with aqueous solutions of BTEX compounds for a pre-defined period of time. Afterwards the sensing phase was removed from the solution, dried and placed in the detection system of an FT-NIR spectrophotometer. Detection limits of 0.079, 0.12, 0.14 and 0.28 mg L for benzene, toluene, ethylbenzene and xylenes, respectively, have been achieved. The sensing phase was applied to the determination of benzene and toluene in water samples contaminated by gasoline, providing results that did not show statistical differences from those obtained by GC-FID at a confidence level of 95%. The sensing phase was also applied to the simultaneous determination of BTX in contaminated water, providing RMSEP values (root mean square error of prediction) of 0.57 mg L for benzene, 2.21 mg L for toluene and 1.23 mg L for xylenes. A near infrared photometer based on LED (light emitting diodes) for the determination of total BTEX was developed. The instrument operates with two LED as light sources and a photodiode as detector, a transmission cell connected to an optical fiber bundles; a VisualBasic.Net program was written for control and data acquisition. The instrument performance indicated that it can be a feasible and low cost alternative for the determination of total BTEX in water. Finally, it was evaluated the performance of the new luminescent reagent bis(1,10-phenanthroline)(2-(1H-imidazol-2- yl)-1H-imidazo[4,5-f][1,10]phenanthroline)ruthenium(II) di(hexafluorophosphate) for the development of an optical sensor for the determination of metal ions in water. The immobilization the reagent in the polymeric matrices showed that the optical sensor is selective to Cu (II) ion, providing a detection limit of 32 mg L. The new complex of ruthenium (II) was also applied to the simultaneous determination of Cu (II) and Hg (II) in aqueous solution, showing RMSEP values 2.12 mg L and 0.95 mg L, respectively

ASSUNTO(S)

nir optode touleno btex (benzo metals nir xileno) optodo metais btex etilbenzeno

ACESSO AO ARTIGO

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