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盐水化合物低温时具有特征的拉曼光谱,已有实验证明这种拉曼光谱适合于判定标准溶液的溶质性质．人工合成流体包裹体作为天然包裹体的参照物,可以被用来验证许多涉及流体包裹体的假设的有效性,也是检验激光拉曼法测定单个流体包裹体溶质性质可行性的关键．本文采用Sterner和Bodnar提出的方法,在50/100MPa,500～600℃范围内合成了纯H_2O体系和NaCl含量为5．12,9．06,16．6,25wt%的NaCl-H_2O体系的流体包裹体．联合使用冷热台和激光拉曼探针,在低温(-180℃)时原位测定采集了冰及水石盐(NaCl·2H_2O)的拉曼光谱．研究表明合成包裹体的盐水化合物(NaCl·2H_2O)具有特定的拉曼光谱,可以做为鉴定自然界水-盐体系包裹体中NaCl存在的标准．包裹体中的水在冷冻后以结晶冰的形式出现,而不是以非晶质的固体(水玻璃)形式出现．初次冷冻后采集的原位拉曼谱显示了明显的冰峰(3098cm~(-1)),但没有典型的水石盐拉曼谱峰出现．随着温度的升高,在-40～-22℃温度区间观察到明显的相变,其代表了水石盐的结晶事件而不是熔化事件,对低于NaCl-H_2O体系低共熔点(-20．8℃)的相转变温度的解释应该慎重．盐水化合物的拉曼谱与冰的拉曼谱的相对强度及截面之比,指示出流体包裹体盐度的相对大小．水石盐的3423cm~(-1)峰与冰峰(3098cm~(-1))的峰高、峰的截面积之比是获得NaCl-H_2O体系盐度信息的比较理想的参数．
Salts have characteristic Raman spectra at low temperatures, and experiments have shown that this Raman spectrum is suitable for determining the solute properties of standard solutions. Synthetic fluid inclusions, as references for natural inclusions, can be used to verify the validity of many hypotheses involving fluid inclusions and to test the feasibility of the laser Raman method to determine solute properties of individual fluid inclusions. In this paper, the pure H 2 O system and the NaCl-H 2 O system fluid with NaCl content of 5.12, 9.06, 16.6 and 25wt% were synthesized by the methods proposed by Sterner and Bodnar in the range of 50/100 MPa and 500-600 ℃. Inclusion. In combination with hot and cold stage and laser Raman probe, the Raman spectra of ice and water stone salt (NaCl · 2H_2O) collected at low temperature (-180 ℃) were measured in situ. The study shows that the brine inclusions (NaCl · 2H_2O) of synthetic inclusions have specific Raman spectra, which can be used as a criterion to identify the existence of NaCl in water-salt system inclusions in nature. The water in the inclusions appeared as crystalline ice after freezing, rather than as an amorphous solid (water glass). The in situ Raman spectra collected after the initial freezing show a clear ice peak (3098 cm -1), but no typical Raman peak appears. With the increase of temperature, obvious phase transition was observed in the temperature range from -40 ℃ to -22 ℃, which represents the crystallization event rather than the melting event of water stone salt, but lower than the eutectic point of NaCl-H 2 O system (-20. 8 ℃) phase transition temperature should be interpreted with caution. The relative intensities and cross-sectional ratios of the Raman spectrum of the brine compound to the Raman spectrum of the ice indicate the relative salinity of the fluid inclusions. The peak height and peak cross-sectional area ratio of 3423cm ~ (-1) and ice peak (3098cm ~ (-1)) are the ideal parameters for obtaining the salinity information of NaCl-H_2O system.