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>Statistical moments of elution bands and their application in gel permeation chromatography of polydisperse macromolecules
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Statistical moments of elution bands and their application in gel permeation chromatography of polydisperse macromolecules
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机译：Statistical moments of elution bands and their application in gel permeation chromatography of polydisperse macromolecules
AbstractEquations have been derived that relate the statistical moments of uncorrected and spreading‐corrected chromatograms for a general form of the spreading function in gel permeation chromatography of polydisperse macromolecules. The first moment (centroid) of the chromatogram is shown to be directly given by the centroid, InM*, of a suitably defined molecular weight distribution function of the polydisperse sample, regardless of the position of the calibration dependence, provided it is linear. Both the molecular weightM*associated with the centroid of the chromatogram and its second central moment (variance) are but little sensitive to the shape of sample molecular weight distribution and can be easily calculated from the polydispersity indexMw/Mn, at least for polymers of a not excessively broad distribution. The derived relations are shown to find application in the calibration of GPC columns by means of characterized, polydisperse standards and in the separation of independent contributions to peak width which originate in sample polydispersity and in band broadening processes in the column. Improved column‐ and packing performance criteria are also propo
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