[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.


METHODS
Thermogravimetry and differential thermogravimetry.


RESULTS
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.


CONCLUSIONS
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.
Yang
L S
LS
Henan College of Traditional Chinese Medicine, Zhenghou 450003, Henan, China.
Zhu
Y
Y
Shen
X Q
XQ
Chang
L K
LK
Xu
M
M
D000818:Animals; D004055:Differential Thermal Analysis; D004340:Drug Contamination; D006358:Hot Temperature; D008419:Materia Medica / Q000737:chemistry*; D008974:Mollusca / Q000737:chemistry*; D011208:Powders; D011786:Quality Control
D008419:Materia Medica; D011208:Powders