Thermochimica Acta, Vol.380, No.1, 19-26, 2001
Sources of error, and their correction, in the analysis of isothermal heat conduction microcalorimetric data: applications of a newly developed test reaction
A recent investigation of a test reaction for isothermal heat conduction microcalorimeters, used for the determination of thermodynamic and kinetic parameters, resulted in the following recommended values for the imidazole-catalysed hydrolysis of triacetin at 298 K: the reaction rate constant, k = (2.80 +/-0.1) X 10(-6) dm(3) mol(-1) s(-1), and the reaction enthalpy change, Delta H-R = -91.7 +/- 3.0 kJ mol(-1). Knowledge of these values allows the performance of a microcalorimeter to be evaluated. Thus, it may be possible to correct data for those cases in which there is mis-assignment of the true instrument baseline zero, of the upper calibration setting and of a drift in the instrument baseline. This paper describes the expected data output and its analysis in these cases. For these instances, it is possible to identify the error source and to manipulate subsequent data to produce "corrected" results. The procedures are illustrated through the use of data simulated as output.