Basic gel permeation chromatography studies. III. Mathematical analysis of peak spreading

Abstract

Peak spreading in gel permeation chromatography has been studied with a range of gels including those whose permeation limit corresponded to about 103, 106, 108, and 109 molecular weight polystyrene. Peak spreading conformed to the equation YV2 = YM2 + YA2 + YI2 + YD2 + YS2, where YV is the peak width of a normal chromatogram, YM is the contribution due to the true molecular weight of the sample, YA is due to peak spreading in the apparatus, YI is spreading in the interstitial volume, YD is diffusional spreading due to time spent in the gel, and YS is due to sorption. Evaluating the appropriate parts of the equation leads to measures of the true molecular weight distribution and the contribution due to diffusion into and out of the gel. The data also allowed estimates as to the diffusional spreading with small molecules. With polystyrene having 100 000 molecular weight, diffusional spreading accounts for 80% of YV,2 but with small molecules the contribution due to diffusion was not detected.

Gel permeation chromatography: The effect of pore size distribution on separation efficiency

“…DeVries4 considered eluting from a given column and also for polymeric solutes. 8 An excellent review of various aspects of peak broadening has been given by Kelley and Billmeyer. l8 Theoretical predictions by Carmichaelg suggested that, for unperturbed random coils, the experimental base widths should decrease with increasing molecular weight for a given column for samples of similar A7m/fln.…”

Recent Advances in Polymer Fractionation

“…Figure 4 shows the over-all plate height plotted against elution volume a s determined by the r e v e r s e flow method [ 2 6 ] . The maximum in the plate height curve has also been observed by Hendrickson [27], and by Yau, Malone, and Suchan [28]. F r o m this zone spreading characteristic of GPC and from other experimental evidences, Yau, Malone, and Suchan [28] have arrived at the following conclusions: (a) They reasoned that the separation by flow as proposed by DiMarzio and Guttman could not have contributed significantly in GPC as the spreading in GPC was o r d e r s of magnitude smaller than what would be observed if separation by flow was the predominant mechanism.…”

A method for estimating the rejection coefficient–molecular weight relationship of ultrafiltration membrane for a chain polymer by using gel permeation chromatography

“…When the spreading can be assumed to be Gaussian, the phenomenon of dispersion in GPC has been described adequately by Tung's integral equation6: ( 5 ) where F(t) represents the observed chromatogram, W(0) is the corrected chromatogram, and t and 8 are the elution times. In this study the resolution factor h is approximated to be a constant, as shown later.…”