Longitudinal diffusion in size-exclusion chromatography: a stop-flow size-exclusion chromatography study.
Band broadening in size-exclusion chromatography (SEC) has an adverse effect upon calculated molecular mass averages, distributions, and dilute solution data generated using single- and multi-detector systems. In the past, the longitudinal diffusion contribution to band broadening in SEC has been considered negligible. This assumption has been investigated by using a stop-flow methodology (SF-SEC) that maximizes the potential for longitudinal diffusion while minimizing that for mass transfer. Under the given experimental conditions, the effects of B-term band broadening were manifest only below 30 KDa, irrespective of chemical functionality or molecular mass polydispersity. This type of broadening was found to be flow rate-independent for a representative high molecular mass polymer.
Striegel
A M
AM
Safety Product Technology, Solutia Inc, Springfield, MA 01151, USA. amstri@solutia.com
D002850:Chromatography, Gel / Q000379:methods*; D004058:Diffusion; D008970:Molecular Weight