| Abstract
| - Size-exclusion experiments of alcohols, mono- anddicarboxylic acids, aromatic acids, and amino acids wereconducted. Two columns with different gel packings(TSK HW 50 S and TSK G2000SW) were used to determinethe influence of the gel core structure on the elutionvolume of organic substances. Neither for the polymerbased gel nor for the silica based gel specific interactions,especially hydrophobic interactions, could be neglected.For both alcohols and monocarboxylic acids the elution volumeincreased with an increasing number of carbon atoms. Itwas found that aromatic compounds interacted strongly withboth gels. Whereas alcohols were not affected bydifferences in ionic strength between sample and eluent,the elution volume of carboxylic acids was strongly influenced.In combination with a multidetector system (UV absorption,fluorescence, dissolved organic carbon, electricalconductivity) changes in the chromatographic behavior ofthese compounds due to differences in ionic strengthbetween sample and eluent were used to interpret size-exclusion results from natural organic matter andligninosulfonic acids. Since most of the substances usedin this work do not absorb UV light nor do they have anyfluorescent capabilities, a continuous-flow DOC detectorwas used to record the chromatograms.
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