低浓度磷酸根对碳酸羟基磷灰石溶解度的影响

目的：测定碳酸羟基磷灰石（CHA）在含低浓度磷酸根的检测溶液中的溶解度，探讨磷酸根对CHA体外溶解过程的影响。方法：采用固体滴定法检测CHA在（37．0±O．1）oC恒温下、含0．5mmol／L磷酸根的0．1mol／LKCl溶液中的溶解过程并绘制溶解度等温曲线。采用扫描电镜（SEM）、X射线衍射分析（XRD）及能谱分析（EDX）检测CHA的理化性能。结果：在KCl溶液中，CHA的溶解度高于羟基磷灰石，低于无机牛骨；在0．5mmol／L磷酸根背景溶液中，CHA的溶解度略有升高。结论：CHA的溶解不遵循经典的热动力学理论规律，其溶解度与pH值相关。低浓度磷酸根可促进CHA溶解。

The effect of low concentration phosphate on the solubility of carbonated hydroxyaptite

Objective： To determine the solubility of carbonated hydroxyapatite （CHA） in aqueous KC1 （0.1 tool / L） and / or KH2PO4 （0.5 mmol / ID atl （37.0 ＋ 0.1）℃ with pH 3.5～5.0. Method： The titration end-point of the solid CHA used was monitored by a low-angle laser-scattering system. Total added solid and the solution pH value were used to identify the solubility of CHA in aqueous KC1 （0.1 mol / L） and / or KH2PO4 （0.5 mmol / L）. The solid titrant was characterized by scanning electronic microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive X-ray spectroscopy （EDX）. Result： The solubility of CHA in 0.1 mol / L aqueous KC1 was higher than that of stoichiometric hydroxyapatite, but lower than that of bovine bone. A slightly increase was observed with 0.5 mmoI / L KH2PO4. Conclusion： The dissolution of CHA does not fol- low the classic thermodynamic theory. Its solubility is related to the solution pH and could be increased by low concentration phosphate.