Rapid delineation of humic and non-humic organic matter fractions in water

Abstract

Dissolved organic matter (DOM) in water is often characterized by aggregate parameters like dissolved organic carbon (DOC). DOM from conventional surface water treatment plant in Northern New Jersey was isolated and fractionated using resin adsorption chromatography into six different fractions, which were operationally categorized as hydrophobic acid, hydrophobic neutral, hydrophobic base, hydrophilic acid, hydrophilic neutral and hydrophilic base. The spectral fluorescent signatures (SFS) technique was developed for the quantitative identification of the six fractions by post-processing analysis that includes a statistical model. The SFS is the total sum of emission spectra of a sample at different excitation wavelengths, recorded as a matrix of fluorescent intensity in coordinates of excitation and emission wavelengths, in a definite spectral window. High sensitivity and rapid identification and quantification of DOM fractions are among the main features of the technique. Since hydrophobic and hydrophilic substances are considered more humic and non-humid in nature, respectively, the technique provided an opportunity to rapidly delineate source waters in terms of such categories.