Comparative investigation of various adding methods on synthesis of calcium phosphate containing Chinese medicine

The purpose of this paper was to investigate the effect of various Chinese medicine adding methods on their contents in calcium phosphate (CaP) and the crystal structure of the CaP comparatively. In the present study, CaP was synthesized by the wet chemistry method, in which starting reagent grades calcium nitrate and diammonium phosphate were used as the molar ratio Ca/P=1.5. Chinese medicine parenteral solution, Salvia Miltirrhiza Bunge (SMB), was added into the Ca2+ and PO43- reactive solutions before, during or after synthesis process. CaP was synthesized without adding SMB as the control. UV-VIS spectrophotometer was used to measure the supernatant absorbency. Zeta potential was used to characterize the various CaP slurries. Thermogravimetry, X-ray diffraction and transmission electron microscope were used to characterize the various powders, respectively. The presented results showed that adding SMB during the reaction can obtain the maximal medicine content among the four different adding methods. There was a slight effect on the crystal structure of CaP by adding SMB.