Characterization of size fractionated dissolved organic matter from river water and wastewater effluent using preparative high performance size exclusion chromatography Kangmin Chon a,b , Kyongmi Chon b,c , Jaeweon Cho d,⇑ a Jeju Global Research Center (JGRC), Korea Institute of Energy Research (KIER), Haemajihaean-ro 200, Gujwa-eup, Jeju-si, Jeju-do 63357, Republic of Korea b School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Cheomdan-gwagiro 261, Buk-gu, Gwangju 61005, Republic of Korea c Chemical Safety Division, National Institute of Agricultural Science (NAS), Nongsaemgmyeong-ro 166, Iseo-myeon, Wanju-gun, Jeollabuk-do 55365, Republic of Korea d School of Urban and Environmental Engineering, Ulsan Institute of Science and Technology (UNIST), UNIST-gil 50, Ulju-gun, Ulsan 44919, Republic of Korea article info Article history: Received 12 April 2016 Received in revised form 27 October 2016 Accepted 9 November 2016 Available online xxxx Keywords: Dissolved organic matter Molecular weight Preparative high performance size exclusion chromatography Metal complexation Pyrolysis-gas chromatography-mass spectrometry abstract Structural and functional characterization of dissolved organic matter (DOM) is challenging due to its inherent heterogeneity and coherent complexity. Here, a relatively new method based on preparative high performance size exclusion chromatography using deionized water as mobile phase (recovery rate of total carbon mass > 97%) was developed to fractionate DOM depending on molecular size and identify molecular weight (MW)-dependent DOM characteristics presumably associated with its potential for for- mation of complexes with inorganic species (i.e. metals and metalloids), membrane fouling and disinfec- tion byproducts. Size fractionated DOM from different types of source (river water vs. wastewater effluent) provided similar patterns in water quality, fluorescence properties and biopolymer composition. This suggested that discharge of municipal wastewater had an impact on the river water. However, the propensity for complexation between each size fractionated DOM sample and various inorganic species was substantially different, due to the differences in fluorescence spectral properties and associated biopolymer composition. Among three distinct size fractionated DOM samples, the fraction with medium MW and the main biopolymers polyhydroxy aromatics exhibited a relatively higher potential for metal complexation and the normalized ratio of metals and metalloids to dissolved organic carbon (DOC) [metal/DOC (fraction i, i = I, II, III)] to [metal/DOC (fraction I)] than the other size fractionated DOMs. The results indicate that the biopolymer composition of DOM plays a critical role in its complexation with inorganic species. Ó 2016 Elsevier Ltd. All rights reserved. 1. Introduction Owing to different sources and mechanisms of decomposition, the structure of dissolved organic matter (DOM) may exhibit varying characteristics with respect to chemical composition, molecular size, functional groups/charge density, aromaticity and hydrophobicity (Thurman, 1985; Leenheer and Croué, 2003; Karanfil et al., 2008; Matilainen et al., 2011). Therefore, various analytical methods, such as UV and fluorescence spectroscopy, high performance size exclusion chromatography (HPSEC), nuclear magnetic resonance (NMR) spectroscopy, Amberlite XAD-8/4 resin, Fourier-transform infrared (FTIR) spectroscopy and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), have been widely used to identify the fate and reactivity of DOM in both engineered (i.e. water treatment processes) and natural systems (Thurman, 1985; Piccolo et al., 2002; Leenheer and Croué, 2003; Karanfil et al., 2008). In aquatic systems, DOM may provide C and energy sources for microorganisms, affect the levels of dissolved O 2 , C, N and P, as well as acidity and mediating photochemical reactions, especially with humic substances (Leenheer and Croué, 2003; Weishaar et al., 2003). Furthermore, it plays an important role in the speciation of trace metals, which is closely associated with their bioavailabil- ity, mobility and toxicity (Kinniburgh et al., 1999). In spite of the importance of DOM in the biogeochemical processes in aquatic systems, it has also been considered as a major water pollutant since it can pose a serious threat both directly and indirectly for drinking water: (i) esthetic concerns (e.g. taste, color and odor), (ii) promotion of bacterial regrowth in water distribution systems, (iii) contribution to flux decline in membrane processes, (iv) increase in demand for coagulants and oxidants and (v) formation http://dx.doi.org/10.1016/j.orggeochem.2016.11.003 0146-6380/Ó 2016 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Fax: +82 52 217 2819. E-mail address: jaeweoncho@unist.ac.kr (J. Cho). Organic Geochemistry xxx (2016) xxx–xxx Contents lists available at ScienceDirect Organic Geochemistry journal homepage: www.elsevier.com/locate/orggeochem Please cite this article in press as: Chon, K., et al. Characterization of size fractionated dissolved organic matter from river water and wastewater effluent using preparative high performance size exclusion chromatography. Org. Geochem. (2016), http://dx.doi.org/10.1016/j.orggeochem.2016.11.003