Estimation of Band Broadening Parameters in Single-Detection Size Exclusion Chromatography

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

Río de Janeiro (Brasil)

Congreso; Macro 2006 - World Polymer Congress, 41 Simposio Internacional de Macromoléculas; 2006

Alternative methods for estimating an asymmetric band broadening (BB) in size exclusion chromatography (SEC) are presented. All methods were developed on the basis of theoretical distributions, such as Poisson or log-normal chain length distributions. Based on a known molar mass calibration, the BB-free mass chromatogram were first determined, and then broadened with several BB functions. The influence of asymmetric (exponentially modified Gaussian) BB functions was investigated for a broad range of parameters (standard deviation and exponential decay). Three different strategies were developed for determining those parameters from theoretically-derived equations involving the peak variances, the location of the inflection points, or the ratio of the slopes calculated at the chromatogram inflection points. The method is simple, as only the first derivative of the mass chromatogram is required. Algebraic equations give information about the operative extent of BB.