Density in the temperature interval (273.65-283.15) K has been experimentally determined for aqueous solutions of of l-tyrosine, l-tryptophan, l-histidine, lphenylalanine and l-proline. These data have allowed the temperature of maximum density (TMD) to be obtained as a function of amino acid concentration. All systems present TMD depression against concentration, which was quantified through the Despretz constant. Compared with other compounds, the studied amino acids show a medium effect over TMD, with Despretz constants ranging from -9.85 mol*kg-1 for proline to -16.6 mol*kg-1 for tyrosine. Partial molar volume has been also calculated from density values in order to perform a thermodynamic consistency test between them and TMD data, obtaining satisfactory results.
Compounds
#
Formula
Name
1
C9H11NO3
3-(p-hydroxyphenyl)-L-alanine
2
C11H12N2O2
L-tryptophan
3
C6H9N3O2
L-histidine
4
C9H11NO2
L-phenylalanine
5
C5H9NO2
L-proline
6
H2O
water
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.