New Methodology for pH Measurements in Fuel Ethanol Using Glass Electrode

    Volume 8, Issue 1 (January 2011)

    ISSN: 1546-962X

    CODEN: JAIOAD

    Published Online: 14 December 2010

    Page Count: 9


    Moutinho da Silva, Ricardo
    Dept. of Analytical Chemistry, Institute of Chemistry, UNESP, Araraquara, São Paolo

    Borges, Paulo Paschoal
    Divisão de Metrologia Química, Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (INMETRO), CEP: 25250-020, Rio de Janeiro, Rio de Janeiro

    Fraga, Isabel Cristina Serta
    Divisão de Metrologia Química, Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (INMETRO), CEP: 25250-020, Rio de Janeiro, Rio de Janeiro

    Stradiotto, Nelson Ramos
    Dept. of Analytical Chemistry, Institute of Chemistry, UNESP, Araraquara, São Paolo

    (Received 28 May 2010; accepted 28 October 2010)

    Abstract

    Studies carried out with glass electrode in anhydrous ethanol and ethanol-water solutions for measuring pH values have shown that this parameter depends on the solution composition, the contact time with the solution, the utilized temperature, and the type of electrolyte used. It was also observed that the glass electrode behavior in an acid medium differs from an alkaline medium. These studies provided correction factors for pH values from 2 to 12, allowing the realization of proper measurements of the hydrogen ionic activity in the ethanol-water and anhydrous ethanol solutions. However, these correction factors could not be applied to the fuel ethanol. Alternatively, a new method was developed for the correction of the pH values, which can be applied in hydrous and anhydrous fuel ethanol samples.


    Paper ID: JAI103192

    DOI: 10.1520/JAI103192

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    Author
    Title New Methodology for pH Measurements in Fuel Ethanol Using Glass Electrode
    Symposium , 0000-00-00
    Committee E01