SEC with Molar Mass Sensors: Estimation of the Band Broadening and of the Corrected Mass Chromatogram

MEIRA, G. R.; YOSSEN, M. M.; VEGA, J. R.

Bratislava

Conferencia; 17th Bratislava International Conference on Macromolecules, Molecular Characterization of Polymers. From Conventional Bulk Methods to Separation Procedures; 2003

International Union of Pure and Applied Chemistry (IUPAC)

This theoretical work investigates two problems associated with the band broadening (BB) when molar mass sensors are used in SEC. The following raw data are assumed: a) a mass chromatogram; b) a light scattering chromatogram; and c) a direct calibration, or (alternatively) a universal calibration plus the Mark-Houwink exponent of the analyzed polymer. The work aims at using a narrow calibration standard for estimating the band-broadening function (BBF). This function is represented by an exponentially-modified Gaussian (EMG), with parameters s and t. In the narrow range of each standard, the BBF is assumed uniform. (A non-uniform BBF would be obtained after repeating the procedure with several calibration standards, and interpolating the EMG parameters). The second part of the work deals with directly calculating the BB-corrected MWD without determining the BBF.