β-丙氨酸水溶液的FTIR-ATR光谱分析:pH效应和分子解离  

FTIR-ATR of aqueousβ-alanine:pH effect and molecular dissociation

作　　者：张玲 张晓武 黄启燊 张韫宏 李前树 ZHANG Ling;ZHANG Xiao-wu;HUANG Qi-shen;ZHANG Yun-hong;LI Qian-shu(Huaxin College of Hebei Geo University,Shijiazhuang 050799,China;The Institute of Chemical Physics,School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 10008l,China)

机构地区：[1]河北地质大学华信学院,河北石家庄050799 [2]北京理工大学化学与化工学院化学物理研究所,北京100081

出　　处：《分子科学学报》2023年第6期479-490,共12页Journal of Molecular Science

基　　金：国家自然科学基金资助项目(41875144).

摘　　要：应用傅里叶变换衰减全反射技术(FTIR-ATR)耦合多元曲线解析-交替最小二乘法(MCR-ALS),详细分析了β-丙氨酸水溶液在pH为1.54~12.52范围内的解离过程.通过差谱分析,获得了β-丙氨酸随pH变化的FTIR-ATR光谱,发现在1 800~1 000 cm^(-1)区间,光谱随溶液pH变化而呈现3种特征变化,对应于β-丙氨酸的阳离子、两性离子和阴离子的3种存在形式.通过MCR-ALS约束优化得到了不同形式β-丙氨酸在pH为1.54~12.52的水溶液中的浓度分布和拉曼光谱.同时,考察了NaCl溶液与水溶液环境对β-丙氨酸存在形式的影响,并测定了β-丙氨酸在水溶液和NaCl溶液中的解离常数.In this work,we present detailed analysis of the dissociation ofβ-alanine solutions over the pH range of 1.54 to 12.52 using the Fourier transform infrared attenuated total reflection(FTIR-ATR)technique combined with Multivariate Curve Resolution-Alternating Least Squares(MCR-ALS)methods.By applying appropriate spectrum subtraction methods,we obtained FTIR-ATR spectra of the solvatedβ-alanine as a function of pH.Discernible changes were identified in the absorption region between 1800 and 1000 cm^(-1).The number of components was calculated using singular value decomposition and evolving factor analysis in the complex system.The concentration profiles and the pure spectrum of three species in aqueous solutions in the pH ranging from 1.54 to 12.52 were gained through MCR-ALS constrained optimization.The effect of aqueous solution environment was also investigated in terms of 200 mmol·L^(-1)NaCl.The dissociation constants of β-alanine in aqueous solutions and NaCl solutions were also determined.

关 键 词：FTIR-ATR Β-丙氨酸 MCR-ALS 解离 

分 类 号：O629[理学—有机化学]