草酸钙结石不同层面的扫描电镜能谱和X线衍射分析

目的:分析草酸钙结石不同层面的化学成分,探讨其形成机制。方法:结合扫描电镜能谱分析(SEM-EDS)和X线衍射(XRD)定性、定量分析24例完整草酸钙结石样本不同层面的化学成分。结果:所有结石均为草酸钙混合结石,均含有磷酸钙成分。SEM-EDS显示结石核心、中间、外周的元素含量C(27.97%、30.83%、33.73%)、Ca(12.05%、9.36%、8.95%)、P(3.28%、2.34%、1.67%)差异存在显著性(P<0.05)。XRD显示核心区域含有草酸钙和磷酸钙晶体,外层区域仅含有草酸钙晶体。结论:联合运用SEM-EDS和XRD对结石的不同层面进行成分分析,能够较为准确地检测结石的组分和物相。草酸钙混合结石可能起始于磷酸钙晶体的聚集,草酸钙晶体在此基础上沉积生长可能是结石逐渐增大的原因。

Analysis of the calcium oxalate stone composition in different layers by SEM-EDS and X-ray diffraction

Objective To analysis the chemical composition of calcium oxalate stones in different layers and study the mechanisms of their formation. Methods 24 calcium oxalate calculus were collected and analyzed in different layers by scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and X-ray diffraction (XRD). Results The 24 mix stones which major constituent was calcium oxalate all contained calcium phosphate. SEM-EDS showed the percentages of carbon in core, middle and outside of the stone were 27.97%, 30.83%, 33.73%, respectively. Those of calcium were12.05%,9.36%,8.95% and phosphorus were 3.28%, 2.34%, 1.67%, which have significant differences (P < 0.05). The XRD indicated that calcium oxalate and calcium phosphate crystals were founded in the core of the stone, while calcium oxalate crystals were founded in the outer layers. Conclusions The results of stone component analysis were more accurate by combining SEM-EDS with XRD. The mixed calcium oxalate stones may originate from the deposit of calcium phosphate crystals and followed by calcium oxalate crystals, which may be the cause of the stone formation.