Isothermal reaction calorimetry can be used for the development of theoretically sound kinetic models, even in the case of complex reactions: In this article, the reliability of a previously developed model is further tested. The N-oxidation of 2-methylpyridine modelled by Sempere et al. (Chem Engng Process 37: 33-46) in a 2 L Mettler-Toledo heat-flow calorimeter, in IQS, Spain, is being studied at Leeds University in a 1 L SIMULAR heat-flow calorimeter. The experimental results are compared with the model developed by Sempere et al. In principle, they corroborated the previous findings. Encountered deviations have been justified; further investigation is suggested.