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Journal of Thermal Analysis and Calorimetry

, Volume 96, Issue 3, pp 673–676 | Cite as

Effects of thermal history on solid state and melting behavior of amino acids

  • M. Ellen Matthews
  • Alan T. Riga
Article

Abstract

Dielectric Thermal Analysis (DETA) of drugs, proteins and amino acids reveals a strongly linear conductivity increase prior to and peaking at the melt, associated with dielectric viscoelastic properties of the material. Premelt onset and peak are shown to depend on thermal history. Comparisons of neat amino acid samples to samples heated to 150 °C; dried in a desiccator; or heated above their melting point and cooled show significant premelt and melt shifts. Melts are also correlated with phase transitions observed by Differential Scanning Calorimetry (DSC). Activation energies attributed to charging in the premelt for amino acids were typically 250 J/mole.

Keywords

Activation energy Amino acids Dielectric thermal analysis (DETA) Differential scanning calorimetry (DSC) Phase transitions 

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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2009

Authors and Affiliations

  1. 1.Buckeye PharmaceuticalsBeachwoodUSA

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