Study of the Effect of Volume Contraction in Methanol–Water Mixtures Used as Solvents for Analytical Purposes: A Student-Centered Project for Practical Learning

• P. G. Rodríguez Ortega ^[1] ; B. Gilbert-López ^[1] ; S. Esteo Donaire ^[1] ; M. Montejo ^[1]
  1. [1] Universidad de Jaén

     Universidad de Jaén

     Jaén, España

     
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 96, Nº 4, 2019, págs. 677-684
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The use of methanol–water mixtures as solvents for sample preparations is common in many instrumental analytical procedures for compound quantification at trace concentration levels. The reliability of the analytical method depends upon several factors including consistency of instrumental setup and calibration, quality of standards used and operator’s lab actions, among others. This proposal describes a student-centered project that relates the concept of molar partial volume and transfer it to an actual and relevant lab situation which aims at promoting critical thinking in undergraduate chemistry students. Through its implementation, students are asked to reflect on the impact that a simple laboratory operation (such as the way of preparing a hydroalcoholic mixture) may have on the accuracy of a pesticide quantification, namely, thiabendazole, using native molecular fluorescence determination.