The study of the sample recovery in the liquid chromatography of complex polymer systems

SISKOVA, A.; MACOVA, E.; VEGA, J.R.; BEREK, D.

Salzburg

Simposio; 30th. International Symposium on Chromatography (ISC 2014); 2014

Complex polymer systems exhibit dispersities in chemical composition or physical architecture. Their exact molar mass and dispersity cannot be directly determined by SEC because the retention volumes are affected by all the molecular characteristics and therefore molecules are not separated by molar masses or composition. For example, it would be necessary to suppress molar mass effect to assess other molecular characteristics. To achieve this goal, the entropy-controlled exclusion retention mechanism can be combined with the enthalpy-driven interaction retention of macromolecules. In this study, liquid chromatography under critical condition (LCCC) and liquid chromatography under limiting conditions of desorption (LCLCD) are used. The aim of this contribution is to highlight the limited sample recovery of LCCC and LCLCD. Our measurements revealed that large part of samples with higher molar mass may stay retained within the LC-columns. The fractions eluted from the LCCC and LCLCD columns were online forwarded into the SEC column. Molar masses of the LCCC and LCLCD polymers that release the column (either with or without a displacer) were substantially lower than the actual.