珍珠的热分解机理及质量分析方法研究

目的 :建立快速、简便的分析实验方法 ,对珍珠粉的真伪进行鉴别 ,并对其质量进行初步评价。方法 :热重(TG)和微分热重(DIG)分析法。结果 :珍珠粉的TG和DTG曲线可以分为两个特征区。第一阶段在250～380℃ ,失重率约3 % ,此为有机质变性与分解阶段 ;第二阶段在600～780℃ ,失重率约为40 % ,为碳酸钙的分解阶段。结论 :利用TG曲线的两个特征区及相应的分数 ,可以对珍珠粉进行表征和鉴别 ,其中第一阶段是对其质量进行评价的重要依据。

A Study on Thermal Decomposition Mechanism and Quality Analysis of Pearl Powder

OBJECTIVE: To establish a rapid and convenient method for distinguishing genuine from sham of pearl powder as well as appraising its quality preliminarily. METHOD: Thermogravimetry and differential thermogravimetry. RESULT: The TG and DTG curves can be divided into two characteristic regions. The first step ranges from 250 to 380 degrees C with a weight loss of about 3%, resulting from the denaturalization and decomposition of organic matter in the powder; and the second step from 600 to 780 degrees C with a weight loss of about 40% resulting from the decomposition of calcium carbonate in the powder. CONCLUSION: According to the two characteristic regions on TG and DTG curves along with corresponding parameters, pearl powder can be appropriately authenticated. Being related directly to the contents of organic matter in pearl powder, the first step is an important criterion for quality appraisal.