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Espectrofotometria de longo caminho óptico em espectrofotômetro de duplo-feixe convencional: uma alternativa simples para investigações de amostras com densidade óptica muito baixa

2009; Brazilian Chemical Society; Volume: 32; Issue: 2 Linguagem: Inglês

10.1590/s0100-40422009000200036

1678-7064

André Luiz Galo, M. F. Colombo,

Water Quality Monitoring and Analysis

INVESTIGATING SAMPLES OF VERY LOW OPTICAL DENSITY.We describe the design and tests of a set-up mounted in a conventional double beam spectrophotometer, which allows the determination of optical density of samples confined in a long liquid core waveguide (LCW) capillary.Very long optical path length can be achieved with capillary cell, allowing measurements of samples with very low optical densities.The device uses a custom optical concentrator optically coupled to LCW (TEFLON ® AF).Optical density measurements, carried out using a LCW of ~ 45 cm, were in accordance with the Beer-Lambert Law.Thus, it was possible to analyze quantitatively samples at concentrations 45 fold lower than that regularly used in spectrophotometric measurements.