Principle of Calorimetric Measurement

The total heat evolution is proportional to the molar enthalpy and to the total number of product molecules created in the reaction. 

The change in temperature (AT) recorded by the ET is thus directly proportional to the enthalpy change and inversely proportional to the heat capacity of the reaction. 

As the heat capacity of most organic solvents is two or three times lower than that of water, enhanced sensitivity is expected in organic solvents. This is the case, provided that AH remains unaltered. This area of investigation is dealt with in detail in a later section. 

Analyte Enzyme(s) used Linear range (mM) Enthalpy change (-kj/mol) 

L-Lactate (or pyruvate) Lactate oxidase/catalase + lactate dehydrogenase 10 nMa ca. 225 

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