Published:Journal of Chromatographic Science,
ISSN 0021-9665Volume
39, Number 3, March 2001, pp. 113-120
Estimation
of Molar Heat Capacities in Solution from Gas Chromatographic Data Károly
Héberger [1] and Miklós Görgényi [2]
[1]Institute of Chemistry, Chemical Research Center, Hungarian Academy of Sciences,
H-1525 Budapest, P.O. Box 17, Hungary
[2]Institute of Physical Chemistry, University of Szeged, H-6701 Szeged, P.O.
Box 105, Hungary
The temperature
dependence of retention data (retention or capacity factors) is measured for
35 aliphatic ketones and aldehydes as model compounds on a dimethylpolysiloxane
stationary phase. A novel model is derived to determine the heat of solution
and the solution molar heat capacities from the fits of the log natural of the
difference of the retention factor and the column temperature (T) versus 1/T
and the temperature arrangement. The convex curvature present in the residual
plots of a former defined equation of ours disappears when applying a newly
defined model. A detailed statistical analysis clearly shows the superiority
of the refined model to the earlier one in a broader temperature range. The
validation of this model is made through a comparison of heat capacity values
taken from literature determined by different methods. The molar heat capacity
of a pure liquid oxo compound is similar to that of when the same compound is
solvated in a stationary phase.
Reproduction
of editorial content of this journal is prohibited without publisher’s
permission.
This
article is available in its entirety by fax for $4.00 per
page.
Visa or MasterCard accepted.
To
order electronicallyclick here or call: 847-647-2900 ext. 1323 or fax request to: 847-647-1155.
Please
indicate JCS volume and issue along with
page numbers.
