title: Chain-length-dependent impact of band broadening on the molar-mass determination of synthetic polymers via size-exclusion chromatography.
abstract: The impact of band-broadening (BB) on the molar-mass determination of synthetic polymers via size-exclusion chromatography (SEC) is systematically studied. BB is simulated using the exponentially modified Gaussian (EMG) model, which combines the two inherent and distinct characteristics contributing to BB in SEC: symmetric Gaussian broadening and asymmetric skewing. It is demonstrated that BB both during the measurement of the analyte itself and during the calibration process has an individual impact on molar-mass determination. In this context, particularly skewing leads to a chain-length-dependent underestimation of molar masses, with deviations of the apparent from the true ones of only a few percent for low molar masses to up to 20% for high ones for reasonable extents of BB. The impact is shown to be independent of the shape of the analyte⬢s molar-mass distribution (MMD) and affects broad and multimodal MMDs similarly to narrow and unimodal ones. As a consequence, strategies are presented for a comprehensive quantitative correction of the observed effects, which may find their application in refined SEC software packages. The potential impact of the findings on general conceptions of repeatability and reproducibility within SEC experiments is discussed.
authors.affiliation: Institut für Physikalische Chemie, Georg-August-Universität Göttingen, Tammannstraøe 6, D-37077 Göttingen, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Wolpers
authors.affiliation: Institut für Physikalische Chemie, Georg-August-Universität Göttingen, Tammannstraøe 6, D-37077 Göttingen, Germany. Electronic address: pvana@uni-goettingen.de.
authors.forename: Philipp
authors.initials: P
authors.lastname: Vana
mesh_terms: D002138:Calibration; D002850:Chromatography, Gel / Q000379:methods*; D008970:Molecular Weight; D016011:Normal Distribution; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D011108:Polymers
keywords: Band broadening; Chain-length dependence; Correction; Simulation; Size-exclusion chromatography