Pure Hydroxyapatite Phantoms for the Calibration of in Vivo X-ray Fluorescence Systems of Bone Lead and Strontium Quantification
Pure Hydroxyapatite Phantoms for the Calibration of in Vivo X-ray Fluorescence Systems of Bone Lead and Strontium Quantification
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DOI：
10.1021/ac401877d
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发表时间：
2013-10-01
影响因子：
7.4
通讯作者：
Pejovic-Milic, Ana
中科院分区：
文献类型：
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作者：
Da Silva, Eric;Kirkham, Brian;Pejovic-Milic, Ana
巴黎石膏[poP，CaSO 4中心点（1）/（2）H2O]是用于校准骨金属定量（即骨锶和铅）的体内X射线荧光（IVXRF）系统的标准体模材料。骨金属定量的IVXRF系统的校准采用相干归一化程序的使用，该程序需要对数据应用相干校正因子（CCF），计算为体模材料和骨矿物质的相对论形状因子的比率。关于poP用于校准骨金属定量的IVXRF系统（包括其化学纯度）的适用性，已经提出了各种问题以及它与骨矿物质（磷酸钙）的化学差异。这项工作描述了一种化学纯羟基磷灰石体模材料的制备，该材料具有已知的组成和化学计量，提出用于校准骨锶和铅定量的IVXRF系统，作为POP的替代品。通过氢氧化物沉淀制备纯Ca（OH）（2），解决了分析物污染的问题，发现其分别使锶和铅的水平达到< 0.7和< 0.3 μ g/gCa。由已知量的化学纯Ca（OH）（2）、由纯Ca（OH）（2）制备的CaHPO 4中心点2 H（2）O、分析物和含HPO 42的固化溶液制备HAp模型。通过粉末X射线衍射光谱法测定，发现该材料的最终晶体结构与NIST SRM 1486（骨粉）的骨矿物质组分相似。
Plaster of Paris [poP, CaSO4 center dot(1)/(2) H2O] is the standard phantom material used for the calibration of in vivo X-ray fluorescence (IVXRF)-based systems of bone metal quantification (i.e bone strontium and lead). Calibration of IVXRF systems of bone metal quantification employs the use of a coherent normalization procedure which requires the application of a coherent correction factor (CCF) to the data, calculated as the ratio of the relativistic form factors of the phantom material and bone mineral. Various issues have been raised as to the suitability of poP for the calibration of IVXRF systems of bone metal quantification which include its chemical purity and its chemical difference from bone mineral (a calcium phosphate). This work describes the preparation of a chemically pure hydroxyapatite phantom material, of known composition and stoichiometry, proposed for the purpose of calibrating IVXRF systems of bone strontium and lead quantification as a replacement for poP. The issue with contamination by the analyte was resolved by preparing pure Ca(OH)(2) by hydroxide precipitation, which was found to bring strontium and lead levels to < 0.7 and < 0.3 mu g/g Ca, respectively. HAp phantoms were prepared from known quantities of chemically pure Ca(OH)(2), CaHPO4 center dot 2H(2)O prepared from pure Ca(OH)(2), the analyte, and a HPO42- containing setting solution. The final crystal structure of the material was found to be similar to that of the bone mineral component of NIST SRM 1486 (bone meal), as determined by powder X-ray diffraction spectrometry.