Calibration and testing of an isoperibolic micro-combustion calorimeter developed to measure the enthalpy of combustion of organic compounds containing C, H, O and N

In order to obtain reliable data of the standard enthalpy of combustion of compounds containing carbon, hydrogen, oxygen, and nitrogen atoms, an isoperibolic micro-combustion calorimeter has been developed from a 22 cm3 1109A Parr semi-micro oxygen bomb. The calorimeter was calibrated with standard benzoic acid and the resulting energy equivalent was ε(calor) = (1497.39 ± 0.37) J · K−1, which means an uncertainty of 0.027%. Combustion measurements using salicylic acid and 1,2,4-triazole were made in order to verify the accuracy of the device. The values of −Δcu° at T = 298.15 K for the compounds were (21877.2 ± 4.6) J · g−1, and (19217.7 ± 1.9) J · g−1, respectively, in agreement with the literature values.

► Calibration and testing of a isoperibolic micro-combustion calorimeter. ► A micro-combustion calorimeter with a high sensibility. ► A micro-combustión calorimeter suitable for determining combustión energy of 30 mg solid samples. ► Determination of ΔcUmo, ΔcHmo and ΔfHmo of the salicylic acid and 1,2,4-triazole.