Sistema autorizado para la determinación fotométrica del punto final en titulaciones Winkler

Authors

  • Omar Calvario-Martínez Unidad Mazatlán en Acuicultura y Manejo Ambiental, Centro de Investigación en Alimentación y Desarrollo, A. C. Sábalo Cerritos s/n, Estero de Yugo. Apdo. Postal 711, Mazatlán 82010, Sin., México.
  • Francisco J. Flores-Verdugo Estación Maztlán, Instituo de Ciencias del Mar y Limnología, UNAM. Explanada de la Azada y Cerro del Crestón, Apdo. Postal 811, Mazatlán 82240, Sin., México.
  • Claudia Saavedra-Rojas Departamento de Biología, Facultad de Ciencias, UNAM, Apdo. Postal 70-572, C.P. 04510, México, D.F.
  • Alicia Cruz-Martinez Departamento de Biología, Facultad de Ciencias, UNAM, Apdo. Postal 70-572, C.P. 04510, México, D.F.

Keywords:

Oxygen, Winkler, Automatic, Primary production

Abstract

A description and evaluation of a system forthe automatic determination of the end-point during Winkler titrations for dissolved  oxygen is presented. The system used a photometric detector which is connected an IBM PC-XT compatible computer through an analogue to digital converter. Thiosulphate was added by means of a piston burette with a serial port for communicating with the computer. The titration of the sample is completely controlled by the computer using a programme specifically designed to simulate manual titration. The process employed allows the determination of thhe end-point of the reaction by means of a photocell with which the subjectivity present in the manual methods is eliminated. The anaysis of the samples is quick (2 to 3 minutes) and precise, with a CV of betwen 0.01 and 0.18% for 3 replicates, which is similar to the values reported by other authors. This system can be used for the determination of phytoplankton production and respiration rates in oligotrophic waters.

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How to Cite

Calvario-Martínez, O., Flores-Verdugo, F. J., Saavedra-Rojas, C., & Cruz-Martinez, A. (2017). Sistema autorizado para la determinación fotométrica del punto final en titulaciones Winkler. HIDROBIOLÓGICA, 8(1), 1–8. Retrieved from https://hidrobiologica.izt.uam.mx/hidrobiologica/index.php/revHidro/article/view/692

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Artículos