Na2CO3-H2O体系人工流体包裹体中CO3^2-离子的显微拉曼光谱研究  

Raman micro-spectroscopy study of carbonate ion in synthetic fluid inclusions in system Na_2CO_3-H_2O

作　　者：潘君屹[1] 丁俊英[1] 倪培[1] 

机构地区：[1]南京大学内生金属矿床成矿机制研究国家重点实验室,地球科学与工程学院,南京210093

出　　处：《南京大学学报（自然科学版）》2012年第3期328-335,共8页Journal of Nanjing University（Natural Science）

基　　金：南京大学内生金属矿床成矿机制研究国家重点实验室研究项目(2008-Ⅱ-11);南京大学大学生创新训练计划项目(XZ1110284009)

摘　　要：本实验利用显微激光拉曼光谱技术,采用可视融合SiO2毛细管样品,在室温(293K)下,针对200cm-1～4000cm-1光谱区间,原位采集了Na2CO3-H2O体系水溶液包裹体的拉曼光谱.并且,在分析包裹体特征拉曼光谱基础上,对流体包裹体中的CO23-离子浓度开展定量分析工作.实验结果显示,水溶液包裹体中CO23-离子具有明显的拉曼特征峰,且其特征峰强度随离子浓度的增加而增强.对CO23-离子的定量分析结果,揭示CO23-离子特征峰的强度参数(I)———CO23-离子特征峰和水O-H伸缩振动特征峰面积比———与CO23-离子浓度(c(CO23-))之间存在函数关系:c(CO23-)=-1244(I)2+132.4(I)+0.042;同时,也证实水是盐水体系水溶液包裹体拉曼定量分析的合适内标,其与检测物的拉曼强度比是具有定量分析价值的参数;此外,还反映排除主矿物拉曼信号干扰,准确获取CO23-离子拉曼特征峰有助于流体包裹体中CO23-离子的精确定量.此次研究结果表明显微激光拉曼光谱技术能够有效应用于水溶液流体包裹体中CO23-离子的定量分析,其不失为流体包裹体成分定量分析的一种实用手段.This work aims to determine the carbonate ion in fluid inclusions by Raman micro spectroscopy. For this purpose, the technique of optical fused silica capillary was applied to synthesize the fluid inclusions in system Na2CO3- H2O and Raman micro-spectroscopy was used to in situ collect the Raman spectra of fluids in capillary samples at ambient temperature （293 K） and in the region of 200-4000 cm ^-1,Also, the concentrations of carbonate ion in fluid inclusions were quantified basing on the characterization of Raman spectra of fluid inclusions. The experiments present that the band of CO2- in aqueous inclusions is characterized and the intensity of the band is stronger with the increasing of the concentration of carbonate ion. After the quantitative measurement of the carbonate ion in fluid inclusions, the results reveal： （1） the function relationship between the parameter of intensity of Raman band of CO2 （I）, which is the ratio of Raman intensity of CO2- band （in 1064 cm^-1） to that of water band （O--H stretching bands between 2800 and 3800 cm^-1）, and the concentration of carbonate ion （c（CO3^2- ））： c （CO3^2-） = --1244 （I） ^2 ＋ 132.4 （I） ＋ 0. 042, （2） the reasonableness to treat water as an internal standard for Raman quantitative measurement of species in salt-bearing aqueous inclusions, which is significant to correlate the ratio of Raman intensity of species to that of water with the concentration of species in fluid inclusions, （3） the necessity of good recognition of band CO3^2- by removing the signal of host mineral including fluid inclusions, which is helpful to precisely determine the concentration of carbonate ion in fluid inclusions. This study indicates that Raman micro- spectroscopy can be effectively used to measure the concentration of carbonate ion in aqueous inclusions and it is a valid method for the quantitative measurement of concentrations of species in salt-bearing aqueous inclusions, which may be widely applied to the natural fluid i

关 键 词：Na2CO3-H2O体系 可视融合二氧化硅毛细管 拉曼光谱 定量分析 

分 类 号：O657.37[理学—分析化学]