海水珍珠和淡水珍珠的热分析鉴别

Differential Thermal Analysis of Seawater and Freshwater Pearls

目的为海水珍珠和淡水珍珠的快速鉴别提供新方法。方法采用热重(TG)-差示扫描量热法(DSC)分别对淡水养殖珍珠、海水养殖珍珠及海水野生珍珠进行热谱扫描。结果 3种珍珠的TG和DSC曲线总体趋势一致,但其峰形、峰值、热分解区间、有机质均存在明显差异;TG法测得海水养殖珍珠中Ca CO3含量较高;DSC曲线显示热焓值绝对值大小与该阶段TG质量损失一致。结论热分析法具有样品无需预处理、图谱易分析的特点,为淡水珍珠和海水珍珠的鉴别研究提供了简便快速的新方法。

Objective In order to establish a new method for the rapid identification of seawater and freshwater pearls. Methods The systematic study of freshwater cultured pearls, seawater cultured pearls and seawater wild pearls were determined by means of thermogravimetric（TG） - differential scanning calorimetry（DSC）, respectively. Results Three kinds of pearls showed similar general trend of thermal analysis curves, but its peak shape, peak, thermal decomposition range,content of organic matter were significantly different; The content of CaCO3 in seawater cultured pearls is high by means of thermogravimetric, and DSC curve shows that the absolute value of the thermal enthalpy is consistent with the mass loss, which is measured by TG at this stage. Conclusion The thermal analysis has the advantage of without pre-preparation, and easy analysis. Therefore, this methods provide a simple and fast way to distinguish freshwater and seawater pearls.