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 relationship 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; however, 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 obtained from fitting curves of the intensity ratio and the concentration in all systems) that the ability affecting of hydrogen bond of water molecules is in such order: CaCl2, MgCl2 > NaCl, FeCl3 > ZnCl2, CuCl2.
Download Full PDF Version (Non-Commercial Use)