Pyrolysis-gas chromatography (Py-GC) and liquid chromatography (LC) are widely used for the characterization of (co)polymers.The combination of organic SEC and Py-GC, either in the off-line mode or on-line hyphenated, has been demonstrated to be able to give highly relevant information on (co)polymers by several authors.Unfortunately, a number of polymers can only be dissolved in aqueous solvents and therefore require aqueous size exclusion chromatography (SEC) or reversed-phase liquid chromatography (RPLC).Evidently, for the automated online coupling of RPLC or aqueous SEC to GC the introduction of large volumes of water or water-containing mixtures is inevitable.