Application of Light Emitting Diodes to Chemical Analysis: Determination of Copper in Water

• Juan D. Mozo ^[1] ; Manuel Galan ^[2] ; Emilio Roldán ^[2]
  1. [1] Universidad de Huelva

     Universidad de Huelva

     Huelva, España

     
  2. [2] Universidad de Sevilla

     Universidad de Sevilla

     Sevilla, España

     
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 78, Nº 3, 2001, pág. 355
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • In this paper a photometer based on a light emitting diode (LED) is described. The apparatus is very simple and easy to build. The light source is a 5-mm LED, which can be replaced in order to select the emission wavelength. A fiber optic is used to conduct light from the LED to the sample. An inexpensive solid-state light-to-voltage optical sensor is used as detector. Using a yellow LED (peak emission = 595 nm), copper(II) in the μg L-1 range can be accurately analyzed. Errors due to the non-monochromatic emission of the LED are also analyzed on the basis of Beer law deviations. For this purpose, emission and absorption bands are modeled by Gaussian curves.