High-performance liquid chromatographic study of dissolved organic matter in natural waters

Surface natural humic water samples free of industrial and domestic inputs were analyzed directly by high-performance liquid chromatography on a TSK gel size-exclusion column system with u.v. detection at 280 nm. Monomeric and polymeric model compounds and humic and fulvic acid standards were used to determine the concentrations of water soluble high molecular weight organic matter and to estimate humus in the samples. For all samples studied, use of a 0.0002 M NaOH solution was shown to give rise to one sharp peak which was applied for determination of total concentrations of dissolved high molecular weight organic matter in the samples. The retention times of several model compounds used were different and longer than those of high molecular weight matter in humic waters. The data obtained by using this eluent were shown to correlate well with the results obtained by u.v., COD and colour determinations. On the other hand, use of distilled deionized water as the eluent resulting in two or more resolved peaks was recommended for separation of humus components and estimation of the concentrations of humic and fulvic acids in natural waters.