Chemometrics characterization of The Llobregat river dissolved organic matter

Abstract The potential use of multivariate chemometric methods for the investigation of the dissolved organic matter (DOM) sources in surface river waters monitored by UV absorbance and excitation-emission fluorescence spectroscopy is shown. The Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) method is applied to the analysis of the excitation-emission multidimensional data matrices acquired at ten different river sampling sites along the basin of the Llobregat river (located at the north-west of the Iberian Peninsula), from its origin to its mouth, during three different monitoring campaigns. The results obtained by MCR-ALS provided information about the compositional changes of the different DOM sources (i.e. humic-, fulvic- or protein-like sources) present in the investigated river samples, about their site distribution along the river basin and about their changes in three different monitoring campaigns. Eight different MCR-ALS components were resolved describing several types of DOM, with different excitation and emission spectra and with distinct distribution profiles along the river sampling sites. A comparative study of each single sampling site describing the changes in their DOM composition during the three monitoring campaigns was also performed.