利用FTIR对海水养殖珍珠中磷的存在形式的研究初探

The Study of Phosphorus in Seawater Cultured Pearls Using FTIR

利用高分辨率傅里叶变换红外光谱技术(FTIR)对比研究了海水养殖珍珠粉末在16 0℃温度下热处理前后的变化。研究发现:海水养殖珍珠在热处理前、后的矿物相都主要为文石型碳酸钙(CaCO3) ;但在16 0℃温度下热处理一段时间后,海水养殖珍珠的红外光谱发生了明显的变化,出现了文石以外的吸收峰,并随着热处理时间的增加,这些吸收峰有增强的趋势。而样品的差热分析(DTA)结果证明:在2 5～16 0℃温度范围内,海水养殖珍珠除发生吸附水的脱失外,无其他热反应发生(见图1)。也就是说明,海水养殖珍珠中除文石外应还含有其他物相存在。该物相经红外光谱分析证实为碳羟磷灰石。相同样品的X衍射(XRD)结果也与这一结论相吻合,证明海水养殖珍珠中存在碳羟磷灰石。

Seawater cultured pearl was studied by high resolution fourier transform infrared spectroscopy (FTIR) both before and after having been heated at 160 centigrade degree. The results of FTIR indicate that the main material in both samples is aragonite (CaCO3). But compared with the spectra of the seawater cultured pearl, there are some changes that happen in that of the heated sample. Some other peaks arise in the latter. And the intensities of these peaks increase with the heating time. Differential Thermal Analysis (DTA) curve of the seawater cultured pearl shows that seawater cultured pearl has no change between 25-160 degrees C except absorbed water evaporating from the sample. All these evidences prove that besides aragonite, there exists something else in the seawater cultured pearl. This component was determined to be pahuite by FTIR spectroscopic analysis. X-Ray Diffraction (XRD) analysis of the same sample came to the same conclusion.