常见氯盐溶液水的拉曼包络线高斯-洛仑兹去卷积分峰定量研究

Gauss-Lorentz Quantitative Research on O—H Stretching Raman Spectra of Water in Common Chlorine Salt Solution

为了探索地质流体中常见阳离子的拉曼光谱定量方法,在室温下对NaCl-H2O,CaCl2-H2O,MgCl2-H2O,CuCl2-H2O,ZnCl2-H2O和FeCl3-H2O体系3 000～3 800cm-1范围水的O—H伸缩振动区域进行了高斯-洛仑兹去卷积分峰,并对所得积分参数进行了分析。结果显示:(1)不同体系拟合后参数比(峰强比、半高宽比和积分面积比)与浓度的线性相关程度不尽相同,但对于所有体系来说拟合峰强度比(低频/高频)与浓度的线性关系均很好,完全符合定量要求,为室温下定量分析这些体系盐溶液,提供了一种便捷、可靠的定量方法。(2)拟合峰的强度比(低频/高频)随浓度的变化,在NaCl-H2O,CaCl2-H2O和MgCl2-H2O体系中,随浓度增加,强度比呈下降趋势,说明分子间氢键逐渐减少;然而在CuCl2-H2O,ZnCl2-H2O和FeCl3-H2O体系却是呈上升趋势,说明分子间氢键逐渐增多,可能与这三个体系均是过渡金属离子氯盐在水中形成络合物作用有关,尚需进一步研究。(3)通过各个体系强度比与浓度关系一次拟合曲线斜率可以看出对水分子氢键的影响能力CaCl2和MgCl2>NaCl;FeCl3>ZnCl2和CuCl2。

In order to explore the Raman spectroscopy quantitative method of common cations in geological fluids, the present paper has systematically studied Raman spectra of NaCl-H2O, CaCl2-H2O, MgCl2-H2O, CuCl2-H2O, ZnCl2-H2O and FeCl3-H2O solutions by Gauss-Lorentz deconvolution integrated peaks. The results shows that： （1）there is a good quantitative rela- tionship between the peak intensity ratio（low-frequency/high frequency） and the concentration for all systems studied, and this result provides a convenient and reliable quantitative method for quantitative analysis of these systems at room temperature. （2） In the NaCl-H2O and CaCl2-H2O and MgCl2-H2O system, with the concentration increasing, the peak intensity ratio （LF/HF） shows a declining trend , and this result suggests that the number of intermolecular hydrogen bonds is gradually reduced; how-ever, in the CuCl2-H2O, ZnCl2-H2O and FeCl3-H2O system, the trend is on the rise; and this result suggests that the number of intermolecular hydrogen bonds is gradually increased; Such a result may be related to the complex that the transition metal ions formed in these three systems , and further studies are needed. （3）It can be seen through the slopes （that are obtaiiaed from fitting curves of the intensity ratio and the concentration in all, systems） that the ability affecting of hydrogen bond of water mole-cules is in such order： CaCl2, MgCl2〉NaCl, FeCl3〉ZnCl2, CuCl2.