Characterization of Dissolved Organic Carbon in Water using Fourier Transform Infrared Spectroscopy

摘要

This paper describes the development of a sample preparation and Fourier Transform Infrared Spectroscopy (FTIR) analysis procedure for characterization of dissolved organic carbon (DOC) in water. The sample preparation procedure consists of deposition of a solid residue from the DOC onto reflective slides for FTIR analysis. To assess the utility of the method, the FTIR measurement results were compared to conventional analysis results using UV spectroscopy, trihalomethane (THM) formation potential measurements and total organic carbon analysis. DOC spiked water samples prepared from reagent grade standard natural organic carbon materials were used in the method development. The spiked samples were also separated into six organic fractions (hydrophobic acid, neutral and base; hydrophilic acid, neutral and base) using resin fractionation column techniques. The FTIR method proved to be effective for identification of the major organic functional groups present in the spiked samples and sample fractions. The sample preparation and FTIR analysis procedure was then used to characterize the DOC content of source and treated waters at several locations within Saskatchewan. The results of these initial investigations indicate the method can effectively identify the major organic functional groups present in source waters and the changes in the major functional groups that occur as the water is subjected to water treatment unit operations and processes. Further, the presence of several key functional groups corresponds to increased potential for THM formation.