Sources of error, and their correction, in the analysis of isothermal heatconduction microcalorimetric data: applications of a newly developed test reaction

A recent investigation of a test reaction for isothermal heat conduction mi crocalorimeters, used for the determination of thermodynamic and kinetic pa rameters, resulted in the following recommended values for the imidazole-ca talysed 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 chang e, Delta H-R = -91.7 +/- 3.0 kJ mol(-1). Knowledge of these values allows t he performance of a microcalorimeter to be evaluated. Thus, it may be possi ble 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 d rift in the instrument baseline. This paper describes the expected data out put and its analysis in these cases. For these instances, it is possible to identify the error source and to manipulate subsequent data to produce "co rrected" results. The procedures are illustrated through the use of data si mulated as output. (C) 2001 Elsevier Science B.V. All rights reserved.