1992 Volume 8 Issue 4 Pages 491-496
The technique described here improves the purity determination of organic compounds through the use of the differential scanning calorimetry (DSC). The dispersion in the slope of a DSC curve has been observed to have great impact on the measurement results. The causes of this dispersion are the bulkiness and high thermal resistance of organic compounds. The sampling method is therefore directly related to the characteristics of the generated DSC curve. Pressing the sample onto the bottom of a sealed sample container improves the reproducibility of the slope. Sample was pressurized at 100kgf for one minute by using a correction jig. The slope of the DSC curve representing a pure sample was obtained from the thermal conductivity of the sample. This value was used for calibration during computation of the sample purity. When conducted in this manner, the determination of purity based on the DSC method yields values with a maximum error of 0.1mol% for samples with a minimum purity of 99mol%.
