Spectroscopy Observation On The Analysis Of Amino Acids Aqueous Solution

Attenuated total reflection(ATR) spectra can obtain high quality infrared spectrum of the aqueous solution quickly, and get the information of interaction between molecules in aqueous solution effectively. Fourier transform infrared-attenuated total reflection technology with fast scanning speed, high signal-to-noise ratio and low detection limit has great advantages in detecting different components. Chemometrics can quickly and efficiently handle a large number of experimental data, to make more chemical information. we present detailed analyses of the dissociation of ?-alanine aqueous solutions by means of Fourier transform infrared attenuated total reflection(FTIR-ATR) technique combined with Multivariate Curve Resolution-alternating Least Squares(MCR-ALS) methods, at the same time, we applied fluorescence spectrum to study the interaction between glycine and the Bis(2-ethylhexyl) sulfosuccinate sodium salt. The main results are as follows:Applying FTIR-ATR technology, we obtained FTIR-ATR spectra of the solvated ?-alanine as a function of pH. The numbers of components of the ?-alanine during the pH changing were calculated using singular value decomposition and evolving factor analysis. The concentration profiles and the pure spectrum of different species in aqueous solution in the pH range from 1.55 to 12.52 were gained through MCR-ALS constrained optimization. We also studied the solution ionic strength on the influence of alanine dissociation. The dissociation constants of ?-alanine in aqueous solutions and NaCl solutions were determined according to the concentration distribution curve. The corresponding theoretical frequencie and the band assignment show a good agreement with the experimental results.The interaction between glycine and sodium dioctylsulfosuccinate(AOT) in water have been gained by steady-state fluorescence probe technique, Where Pyrene was used as a fluorescence probe. The results show that the CMC of AOT in pure water is 2.97 mmol·L-1, Nagg is 19. As the increase of glycine concentration from 0 mol·L-1 to 1 mol·L-1, CMCs of AOT decrease from 2.97 to 1.26 mmol·L-1 and Nagg values increase from 19 to 37. Based on the I372/I383 as the function of the glycine concentration, it can be concluded that micro-polarity of micelles also decreased with the increasing of glycine concentration in the solutions.