| Abstract: | Effect of inorganic salts in Sephadex-gel chromatography of aquatic organic substances were studied using Sephadex G-15 and samples of peatbog water, river water, and a secondary effluent. A substantial proportion of organic substances from all the water types showed a pH-dependent reversible adsorption affinity to the gel matrix. The presence of inorganic salts in the samples before fractionation can manifest itself in entirely misleading results of the separation of organic substances according to their molecular weights, as it causes the formation of peaks of organic substances. These peaks appear due to the changes in pH within the gel column during elution of inorganic salts and contain molecules of similar adsorptive and dissociative properties rather than those of similar molecular weights. The use of Sephadex-gel chromatography for the correct determination of molecular weight distribution of aquatic organic substances is briefly discussed. |
