Optimization of Method for Detecting and Characterizing NOM by HPLC−Size Exclusion Chromatography with UV and On-Line DOC Detection

Abstract

High-performance liquid chromatography (HPLC)-size exclusion chromatography (SEC) with ultraviolet absorbance (UVA) and on-line dissolved organic carbon (DOC) detectors has been adapted and optimized under various conditions. An enhanced HPSEC-UVA system employing a modified commercially available DOC detector provides a better understanding of the qualitative and quantitative natural organic matter (NOM) properties in water samples by detecting aromatic and nonaromatic fractions of NOM as a function of molecular weight (MW). The most critical merit of this system is that the DOC detector is readily available and widely used. With only a few modifications, a commercially available TOC analyzer served as a DOC detector, integrated with the HPSEC to measure DOC along with UVA, and provided a specific UVA (SUVA) chromatograph that is useful information for drinking water plant design and operation. Without preconcentration, samples can be analyzed with a small amount of sample, with a DOC detection limit as low as 0.1 mg/L (as DOC).

Selective incorporation of dissolved organic matter (DOM) during sea ice formation

“…Measurements were performed using absorbance detection at 254 nm with a Hewlett Packard 1100 series high-performance liquid chromatography (HPLC) instrument. All samples were diluted with ion-exchanged Milli-Q water to a final salinity of 9 to avoid a shift in molecular size due to changes in salinity (Specht and Frimmel, 2000;Her et al, 2002). A baseline correction was performed by normalizing all chromatograms to the absorption at the retention time (Rt) of 12 min.…”

Study of the pH influence on the optical properties of dissolved organic matter using fluorescence excitation–emission matrix and parallel factor analysis

“…DOM is a heterogeneous mixture of various molecular weight aromatic and aliphatic organic compounds that contain oxygen, nitrogen, and sulfur functional groups (e.g., carboxyl, phenol, enol, alcohol, carbonyl, amine, and thiol) [1,2]. The properties of DOM strongly affect its reactivity in both natural and engineered aquatic systems [1,[3][4][5][6][7].…”

A Large Review of the Pre Treatment

“…Its values refer to"mass of organic bound carbon" (OC), not to total mass of compounds. The underlying principle is the diffusion of molecules into the resin pores (Her et al,2002;Serkis & Purdue,1990). This means that larger molecules elute first as they cannot penetrate the pores very deeply, while smaller molecules take more time to diffuse into the pores and out again.…”

“…Then, polysaccharides foster the microbial attachment onto the reverse osmosis membranes, and these high molecular weight compounds can also be used as nutrients by the bacteria, thus facilitating the development of a biofilm onto the membranes. The NOM characterization through LC-OCD chromatography allows to demonstrate that the NOM content (Her et al,2002;Mitra et al,2009) may vary depending on the seasons. Figure 5 notably shows that samples collected during fall have lower polysaccharides levels than samples during summer .…”