High performance liquid chromatography (HPLC)-size exclusion chromatography (SEC) with UV and on-line total organic carbon (TOC) detection has been optimized and evaluated under various conditions. A newly developed HPSEC-UVA-TOC technique provides a better understanding of qualitative and quantitative natural organic matter (NOM) properties in water samples by detecting hydrophobic and hydrophilic (aromatic and non-aromatic) MW fractions of NOM. NOM properties in drinking water sources in terms of MW are significant for designing and optimizing water treatment facilities. A modified Sievers Turbo Total Organic Carbon Analyzer has integrated with the HPSEC to measure DOC along with UVA, providing a SUVA chromatograph that is useful information for drinking water plant design. Without preconcentration, samples can be analyzed with a small amount of sample and a detection limit as low as 0.1 ppm. Includes 7 references, tables, figures.