Saturday, May 24, 2008

Calorimetry

Calorimetry is the study of heat reading in chemical changes or physical changes. It is a thermoanalytical method that measure changes in enthalpy or heat during when the reaction is in progress. [1]

Types of Calorimetry:
There are two main types related to calorimetry:

1. Constant pressure calorimetry.
This measures heat at constant pressure, and represented by "qp" or delta H.

2. Constant Volume calorimetry.
This measures heat at constant volume and represented by "qv" or delta E. [2]

Other types are as follows:

Scanning calorimetry:
(Julian M. Sturtevant) In this calorimeter, there is the measurement of the specific heat of the system as the function of the temperature. Differential scanning Calorimetry is the measurement of the change of the difference in the heat flow rate to the sample and to a reference sample while they are subjected to a controlled temperature program. [3]

Indirect calorimetry:
(D. C. Simonson et al.)Indirect calorimetry is the net rate of disappearence of a substrate (It is not importantly the metabolic changings that the substrate may undergo before its removal from its metabolic pool.)

References:
[1] Handbook of Thermal Analysis and Calorimetry by Michael E. Brown, Patrick K. Gallagher. Elsevier Publishing, 2003.

[2] Chemistry and Chemical Reactivity by John C. Kotz, Paul M. Treichel, Gabriela C. Weaver
Published by Thomson Brooks/Cole, 2005.

[3] Differential Scanning Calorimetry By G.W.H. Höhne, W.F. Hemminger, H.-J. Flammersheim, Published by Springer, 2003

D. C. Simonson, R. A. DeFronzo , Indirect calorimetry: methodological and interpretative problems. American journal of Physiology, Endocrinology and Metabolism 258: Pages E399-E412, 1990.

Julian M. Sturtevant, Biochemical applications of differential scanning calorimetry. Annual Review of Physical ChemistryVol. 38: 463-488. 1987.

Further Reading:
Principles of Thermal Analysis and Calorimetry by P.J. Haines

Comprehensive Handbook of Calorimetry and Thermal Analysis by The Japan Society of Calorimetry and Thermal Analysis

Journal of Thermal Analysis and Calorimetry

Calorimetry and Thermal Analysis

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