2D correlation spectroscopy is a technique where the spectral intensity is defined as a function of two independent spectral variables. With an external perturbation, the selection of the reference spectrum may affect the results of 2D correlation analysis. In many cases, 2D correlation spectroscopy has been used to separate highly overlapped peaks. In this report, the effects of separation have been tested in the generalized situations using simulated spectra with different reference spectra and assuming the intensity changes of bands take the exponential forms. It has been found that it provides more useful information by using time-averaged reference and none reference at the same time.

Key words: 2D correlation spectroscopy, reference spectrum, overlapped band