高温高压下水溶液中硫酸根离子浓度的拉曼光谱定量测定研究  

Raman Spectroscopic Study on the Determination of SO_4^(2-) Concentration in Aqueous Solution under High Temperature and Pressure

作　　者：田锋[1] 郑海飞[1] 孙樯[1] 

机构地区：[1]造山带与地壳演化教育部重点实验室,北京大学地球与空间科学学院,北京100871

出　　处：《光谱学与光谱分析》2015年第4期924-928,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(41373057,41073048);国家(973)项目(2006CB403508)资助

摘　　要：当前,拉曼光谱通常被应用于定性研究,拉曼光谱的定量研究明显不足。通过理论分析,拉曼光谱的定量研究应当基于其相对强度来进行。据此,通过对三种不同浓度的Na2SO4溶液进行拉曼光谱分析,得到了常温常压下水溶液中SO2-4离子浓度的定量方程为:c(SO2-4)=4.779 6R(r2=0.999 4)。此外,对高温高压下硫酸根水溶液的拉曼光谱也进行了研究。光谱分析表明,温度和压力将影响拉曼谱峰强度比值与SO2-4浓度的关系。高温高压下水溶液中SO2-4浓度的定量方程为:c(SO2-4)=4.779 6(R+1.469×10-4ΔT+1.340×10-4ΔP),式中c(SO2-4)为待测溶液中SO2-4的浓度,R为拉曼谱峰强度的比值R(SO2-4/H2O),ΔT为相对于常温(23℃)时的温度差,ΔP为相对于常压(0.1MPa)时的压力差。该方程适用的温度范围为23℃≤T≤360℃,浓度范围为0.5~1.5mol·L-1,测量的相对误差为6.5%。对于具有拉曼活性的物质,拉曼光谱实验技术可以用来进行水溶液中物质浓度的定量研究。In the present work ,the Raman spectra of SO4^2- ions in aqueous solutions were studied .The quantitative analysis shows that there is a significant correlation between the Raman intensity ratio （R） and the SO4^2- concentration .The SO4^2- concen‐tration in aqueous solution at ambient temperature and pressure can be determined by the Raman intensity according to the linear fitting equation c（SO4^2- ）=4.779 6R（r^2 =0.999 4） .Furthermore ,the research proves that the temperature and pressure will af‐fect the relationship between the Raman intensity ratio and the concentration of SO 4^2- ions .The quantitative equation for measur‐ing the SO4^2- concentration in aqueous solution at high temperature and high pressure is c（SO4^2- ）=4.779 6（R＋1.469 × 10^-4ΔT＋1.340 × 10^-4ΔP ） ,where R is defined as the ratio of the SO4^2- ions band intensity to the OH stretching single band intensity ,ΔT is the temperature relative to 23 ℃ ,ΔP is the pressure relative to 0.1 M Pa ,23 ℃ ≤ T≤390 ℃ ,the concentration range of the SO4^2- ions is 0.5~1.5 mol · L^-1 ,and the uncertainty of the equation is 6.5% .Raman spectroscopy can be used to measure the concentration of the Raman‐active species in aqueous solutions .

关 键 词：金刚石压腔 拉曼光谱 高温高压 定量 

分 类 号：O657.3[理学—分析化学]