Uncommon multivariate statistical methods for environmental studies: a review

In this paper we describe the characteristics and the applications of the multivariate methods for spectroscopic and chromatographic techniques I ndependent Component Analysis (ICA) and Two- Dimensional Correlation Spectroscopy (2DCOS) focuse d to their use in environmental studies. In our opinion, these methods are important because th ey allow to characterize environmental samples with different aims and scopes from those generally obtained by means of more common multivariate methods such as Principal Compone nt Analysis (PCA) and Partial Least Squares (PLS). The new insights of these methods in recent environmental studies are reviewed and debated.