Fluorescence and Principal Component Analysis and Parallel Factor (PARAFAC) Analysis: New Criteria for the Characterization of Dissolved Organic Matter in aquatic Environments

摘要

Dissolved organic matter (DOM) consists of a mixture of macromolecular compounds with wide ranging chemical properties and diverse origins. Fluorescence spectroscopy has been applied for characterizing fluorescence properties of DOM for several decades. This technique yields important information on the dynamics and chemical nature of bulk DOM as a function of its fluorescence intensity and fluorescent functional groups. The monitoring of the fluorescent DOM has often been used to distinguish between water masses from various sources, to follow the distribution of water masses or, equally to study the mixing processes in coastal and estuarine waters. In the 1990s, three-dimensional excitation emission matrix (EEM) spectroscopy came into more common use for characterizing fluorescence properties of DOM. EEM spectroscopy provides highly detailed information and the data can be analysed as excitation spectra, emission spectra or synchronous scan spectra. This technique reveals the complete photophysical system of the complex multi-chromophore macromolecular DOM even in the presence of smaller molecules.