奶粉中羟基磷灰石成分的检测

将奶粉溶于超纯水中,经超声、离心、真空冷冻干燥提取奶粉中无机成分富含物,再经X射线粉末衍射(Xray powder diffraction,XRD)和傅里叶红外光谱法对其进行定性鉴别分析;于空白奶粉样品中加入不同浓度的针状纳米羟基磷灰石标准品,经与样品相同处理后进行XRD分析,利用扫描电子显微镜(Scanning electrons microscopy, SEM)、透射电子显微镜—能谱仪(Transmission electron microscopy-energy spectrometer,TEM-EDS)对样品及加标样品中提取成分进行了形貌和纳米尺寸表征。结果表明,加标样品XRD检测中确定含有羟基磷灰石成分,电镜下能观察到纳米尺寸的针状羟基磷灰石,因此验证了此方法检测纳米羟基磷灰石的可行性;5种样品中1种样品含有羟基磷灰石,并含有未知结构的类似于球状的纳米成分(元素组成为碳、氧、磷、氯),3种样品含有晶体状的方解石,1种样品不含有晶体状羟基磷灰石。

Detection of hydroxyapatite in milk powder

The milk powder was dissolved in ultrapure water, and the inorganics-rich components in the milk powder were extracted after ultrasonication, centrifugation and vacuum freeze-drying, and the inorganics-rich components in the milk powder were qualitatively analyzed by X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy. In addition, different concentrations of needle-like nano-hydroxyapatite reference standard were added to the blank milk powder sample, and the same prelimina-ry treatment and analysis as the milk powder samples was carried out. The morphology and nano-size of the inorganics-rich components in sample 1 and spiked sample were characterized by scanning electron microscopy (SEM) and transmission electron microscopy connected with energy spectrometer (TEM-EDS). The results showed that the spiked samples were determined to contain hydroxyapatite component in the XRD test. The needle-like nano-hydroxyapatite can be observed under electron microscope, thus verifying the feasibility of this method for detecting nano-hydroxyapatite. Among five samples, one sample contained hydroxyapatite in the XRD test and a spherical nano-component with unknown structure (the element composition was C, O, P, Cl); while three samples contained crystalline calcite and one sample did not contained crystalline hydroxyapatite.