Characterization and quantification of humic substances 2D-Fluorescence by usage of extended size exclusion chromatography

Abstract

In this article, two methods for in-depth analysis of humic substances fluorescence are presented. The first one allows the combined analysis of fluorescence excitation-emission matrix (EEM) with chromatography technique. The main issue is the coupling of size exclusion chromatography (SEC) with spectroscopy by the use of an absorption and a fluorescence spectrometer as additional detectors. These allow a detailed characterization of humic substances depending on their molecular size, concentration and optical properties. For the evaluation of the resulting complex data, a model based on non-negative matrix factorization, which is also presented in this article, was developed. From the results of the examined humic substances standards, the second method was developed. It allows the characterization and quantification of humic substances fluorescence of a natural water sample solely on the basis of an excitation-emission matrix. The validation of the model is carried out within the framework of extensive analysis of real water samples.

Keywords: Fluorescence; Humic substances; Matrix factorization; Size exclusion chromatography.