Fatty Compounds II

Available online 10 January 2013

 

Activity coefficient at infinite dilution measurements for organic solutes (polar and non-polar) in fatty compounds – Part II: C18 Fatty Acids

  • Patrícia C. Beltinga, b,
  • Jürgen Rareya, Corresponding author contact information, E-mail the corresponding author,
  • Jürgen Gmehlinga,
  • Roberta Cerianic,
  • Osvaldo Chiavone-Filhod,
  • Antonio J.A. Meirellesb
  • a Carl von Ossietzky Universität Oldenburg, Technische Chemie (FK V), D-26111 Oldenburg, Federal Republic of Germany
  • b Food Engineering Department, Faculty of Food Engineering, University of Campinas, Av. Monteiro Lobato 80, Cidade Universitária Zeferino Vaz, 13083-862, Campinas-SP, Brazil
  • c Faculty of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, Cidade Universitária Zeferino Vaz, 13083-852, Campinas-SP, Brazil
  • d Chemical Engineering Department, Federal University of Rio Grande do Norte, Av. Senador Salgado Filho S/N, 59066-800, Natal-RN, Brazil
Corresponding author contact information
Corresponding author. Tel.: + 49 441 798 3846 ; fax: + 49 441 798 3330.

Received 17 December 2012
Accepted 23 December 2012
Available online 10 January 2013

 

1. Introduction

2. Experimental

3. Theoretical Background

4. Results and discussion

5. Conclusions

Acknowledgment

References


Abstract

In this work, activity coefficients at infinite dilution (View the MathML sourceView the MathML source) have been measured for 21 solutes (subscript 1) (alkanes, cycloalkanes, alkenes, aromatic compounds, alcohols, esters, ketones and halogenated hydrocarbons), in 4 solvents (subscript 3), namely one saturated fatty acid and 3 unsaturated fatty acids: stearic (octadecanoic) acid – C18:0, oleic (cis-9-octadecenoic) acid – C18:1 9c, linoleic (cis,cis-9,12-octadecadienoic) acid – C18:2 9c12c and linolenic (cis,cis,cis-9,12,15-octadecatrienoic) acid – C18:3 9c12c15c, by gas-liquid chromatography. The measurements were carried out at temperatures from (303.13 to 368.19) K and the partial molar excess Gibbs energy (View the MathML sourceView the MathML source), enthalpy (View the MathML sourceView the MathML source), and entropy (View the MathML sourceView the MathML source), at infinite dilution were calculated from experimental View the MathML sourceView the MathML sourcevalues obtained over the temperature range. The uncertainties in determination of View the MathML sourceView the MathML sourceand View the MathML sourceView the MathML sourceare 4% and 20%, respectively. The results for stearic acid obtained in this study have been compared to those available in the Dortmund Data Bank (DDB). The real behaviour of fatty systems could be better understood through the results obtained in this work.


Highlights

► Limiting activity coefficients for 21 solutes in 4 C18 fatty acids were measured. ► Thermodynamic functions were derived for stearic, oleic, linoleic & linolenic acids. ► Different trends for polar and nonpolar solutes could be identified. ► The cis-double bonds in the fatty acid alkyl chain influence the View the MathML sourceView the MathML sourcevalues.

Keywords

  • Stearic acid;
  • Oleic acid;
  • Linoleic acid;
  • Linolenic acid;
  • Limiting activity coefficient;
  • Gas-liquid chromatography method

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