Water Content Determination in Biodiesel: Optimization of Methodology in Coulometric Karl Fischer Titration

    Volume 7, Issue 2 (February 2010)

    ISSN: 1546-962X

    CODEN: JAIOAD

    Published Online: 21 December 2009

    Page Count: 7


    Vicentim, M. P.
    Laboratório de Análise Orgânica, Divisão de Metrologia Química, DIMCI/INMETRO, 50 Prédio 6, Xerém, Duque de Caxias, Rio de Janeiro

    Barreto Sousa, M. V.
    Laboratório de Análise Orgânica, Divisão de Metrologia Química, DIMCI/INMETRO, 50 Prédio 6, Xerém, Duque de Caxias, Rio de Janeiro

    Fernandes da Silva, V.
    Laboratório de Análise Orgânica, Divisão de Metrologia Química, DIMCI/INMETRO, 50 Prédio 6, Xerém, Duque de Caxias, Rio de Janeiro

    Mateus, V. Lionel
    Laboratório de Análise Orgânica, Divisão de Metrologia Química, DIMCI/INMETRO, 50 Prédio 6, Xerém, Duque de Caxias, Rio de Janeiro

    Rodrigues, J. M.
    Laboratório de Análise Orgânica, Divisão de Metrologia Química, DIMCI/INMETRO, 50 Prédio 6, Xerém, Duque de Caxias, Rio de Janeiro

    Smarçaro da Cunha, V.
    Laboratório de Análise Orgânica, Divisão de Metrologia Química, DIMCI/INMETRO, 50 Prédio 6, Xerém, Duque de Caxias, Rio de Janeiro

    (Received 12 June 2009; accepted 13 November 2009)

    Abstract

    Coulometric Karl Fischer (KF) titration is a highly accurate technique employed for moisture determination in non-aqueous solvents. Methodology for coulometric titration in a KF apparatus coupled to an autosampler oven was optimized in order to improve the accuracy of moisture determination in biodiesel derived from soybean. Several parameters were investigated, and three of them were optimized according to a central composite 23 star experimental design. The highest accuracy for moisture determinations corresponded to a relative standard deviation of 1.48 %. It was reached when the KF titrator was operated with electrode without diaphragm, the sample mass was 4 g, and the oven temperature was set to 170°C. Other parameters, like carrier gas flux and extraction time, presented minimal or no effects for improving the accuracy of moisture determination.


    Paper ID: JAI102615

    DOI: 10.1520/JAI102615

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    Author
    Title Water Content Determination in Biodiesel: Optimization of Methodology in Coulometric Karl Fischer Titration
    Symposium , 0000-00-00
    Committee D02