Effect of band position shift on moving-window two-dimensional correlation spectroscopy

Effect of band position shift on moving-window two-dimensional (MW2D) correlation spectroscopy was investigated by using simulated spectra. A correlation peak shift along perturbation direction is visualized in the MW2D correlation spectrum constructed from the spectral band position shift data. Two different MW2D correlation patterns are observed from different types of shift data. One correlation peak shift is obtained from band position shift data with a large spectral intensity variation. On the other hand, two correlation peaks are generated from band position shift data with a small intensity variation. MW2D correlation map patterns constructed from similar spectral shape variations of one band position shift and two highly overlapped bands intensity variations are clearly distinguished by the MW2D correlation analysis. Two highly overlapped bands intensity variations never indicate correlation peak shift in the MW2D correlation spectrum. However, overlapped band with band position shift shows correlation peak shift in the MW2D correlation map. MW2D correlation pattern generated from band width broadening data is also discussed. These results can support interpretations of highly complex spectral variations in a practical analysis.