目視観察によるDSC測定
DSC曲線は、理解できない効果を示すことがよくあります。このような場合、サンプルに起きている事象の観察が非常に役立ちます。
顕微鏡オプションに含まれるデバイス
DSC顕微鏡システムには、DSC温度プログラムと同期する画像キャプチャおよび処理ソフトウェアを備えたCCDカメラが含まれています。
アップグレードの可能性
DSCは、反射光顕微鏡測定機能を含むDSC顕微鏡システムにアップグレードすることができます。
品番: 51143087
| 手法 | 示差走査熱量測定 (DSC) |
| タイプ | 光学分析 |
| アクセサリ | あり |
| オプション | 不可 |
 | | DSC-microscopy analysis of an active pharmaceutical ingredient The melting point is an important characteristic property of a substance. The DSC measurement of an active pharmaceutical substance (API) yielded a curve with two main peaks – an endothermic peak with a maximum at 210.8 °C and an exothermic peak at about 228 °C. A smaller peak was also apparent between these two peaks at about 214 °C. The initial interpretation was that the endothermic peak at 210.8 °C is due to melting. The DSC-microscopy results, however, told a different story. No melting was observed at 211 °C – the first signs were detected at about 214 °C. Clearly, the endothermic DSC peak is not caused by a melting process. The color change of the molten substance leads one to conclude that it decomposes immediately on melting. The small DSC peak observed at about 214 °C is therefore the sum of two simultaneously occurring effects – endothermic melting and exothermic decomposition. Separate TGA-MS measurements showed that the endothermic DSC peak at 210.8 °C is caused by the evaporation of water of crystallization. |
 | Dehydration of CoCl2 hexahydrate The images illustrate the dehydration process of cobalt (II) chloride hexahydrate when it is heated from 30 °C at 1.5 K/min. The initial ruby-red color becomes lighter and lighter until it suddenly changes at about 55 °C. Further color changes are observed between 100 °C and 120 °C and at 160 °C. The differences can be quantified by calculating a curve showing image brightness as a function of temperature. The DSC curve shows a broad endothermic peak up to 80 °C with a sharp peak at about 55 °C superimposed on it. Two further endothermic peaks follow at about 104 and 130 °C. The brightness first increases and then suddenly decreases at about 55 °C. Afterward, it increases again in several steps. The peak at about 55 °C is due to a change in crystalline structure. The images around 55 °C show small droplets of water on the surface of the crystals. This indicates that part of the water of crystallization eliminated from the crystal lattice during the solid- solid transition collects on the surface of the crystals and then evaporates. This is completed by about 80 °C. The two broad endothermic peaks on the DSC curve and the step-like changes in the brightness are due to further loss of water of crystallization. | |
