The chromatograms have significant "nonchemical" varietion such as retention time shifts. Such variation will affect the multvariate models and obscure the relevant chemical information. Therefore, a wide array of methods has been devised has been devised to account for retention time shift or remove it altogether from the raw signals model. It depends on the fast Fourier transform and a greedy algorithm for the optimization, which means that each signal is independently aligned to a target by maximizing the cross-correlation between user-defined intervals. Compared to the widely used alignment algorithm, the Correlation Optimized Warping (COW), icoshift has been proved to perform better in terms of alignment quality and require far less computation time. Consequently, icoshift was selected inthis study to align chromatographic signals.