Estimation of the Band Broadening Parameters in Single Detection Size Exclusion Chromatography: A Comparative Study of Various Column Combinations

SCHNOLL BITAI, I.; VEGA, J.R.

Amsterdam (Nederland)

Congreso; Third International Symposium on Separation and Characterization of Natural and Synthetic Macromolecules (SCM-3); 2007

SCM

Alternative approaches for the determination of band broadening (BB) in size exclusion chromatography were used to investigate the column performance of several column combinations (chosen in order to have the complete separation range from 103 to 3×106 gmol-1 which is of interest in many applications). The new method is based on the assumptions that the MWD of narrow polymer standards can be regarded as being a Poisson distribution and that BB can be described by an asymmetric (exponentially modified Gaussian, sBB, tBB) function. Based on the analyses of simulated chromatograms functions were formulated that correlate the measured peak width (defined via the inflection points), the variance and the asymmetry with the BB parameters and the corresponding values of undisturbed Poisson distributions. Combination of two equations at a time leads to three different strategies for the determination of BB parameters. The first experimental results are summarized in the figure; it can be seen that sBB increases and tBB decreases with increasing retention volume.