Data treatment in sequenced two-dimensional liquid chromatography

VEGA, J.R.; SISKOVA, A.; CLEMENTI, L.; BEREK, D.; MEIRA, G.

Salzburg

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

Liquid chromatography at limiting condition of desorption (LC LCD) is a fractionation technique useful for the separation of complex polymer systems. It employs barriers of small molecules for the selective deceleration of more adsorbing species, while other non-affected macromolecules elute in the SEC mode. The LC LCD peaks can be online forwarded into a size exclusion chromatography (SEC) system, for evaluation of average molar masses. This last procedure is called ?sequenced two-dimensional liquid chromatography? (S2D LC). Data treatment of the chromatograms obtained in a S2D LC procedure is difficult because: (i) species unaffected by the barriers suffer of band broadening (BB) in the first-dimension LC LCD column, which in turn depend on the analyzed species and their molar masses; (ii) an additional BB is introduced by the SEC column and intermediate capillaries, valves, and fittings; and (iii) molar masses are calculated on the basis of a molar mass calibration that is determined for the SEC system only, and therefore a proper synchronization of the S2D LC chromatogram with the calibration is required. In this work, a data treatment method is proposed for properly evaluating the S2D LC chromatograms. Initially, the independent BB effects introduced by the different components of the experimental setup are evaluated. Then, a numerical method is proposed for correcting the BB and synchronizing the chromatogram with the available molar mass calibration.