Capillary gel electrophoresis for characterization of dissolved organic substances in environmental waters

A high-performance gel electrophoresis for organic substances in environmental water using a polymer-based sieving media was investigated as an alternative separation method for a conventional high-performance gel-permeation chromatography. Effective separation conditions were investigated, as shown in the following. A sample was injected with electromigration (15 kV, 60 s), separated in a polyethyleneglycol coating capillary (DB-WAX; 0.1 mm i.d.×40 cm, effective length 32.5 cm) filled with a 0.1 M Tris-CHES buffer solution containing 0.5% methylcellulose with an applied voltage of 15 kV and detected selectively at 254 nm using a mercury lamp. We found descrimination of humic substances, such as a humic acid and fluvic acid, from the peak pattern of an electropherogram. We also obtained a several-peak separation of concentrated lake water samples within 6 min, and could estimate the main peak assignment using the above method.