Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
Size‐exclusion chromatography (SEC) is a standard technique for determining molar mass averages and molar mass distributions (MMDs) of polymers. Sometimes the termsgel permeation chromatography (GPC) or gel filtration chromatography (GFC) are also used, but SEC should be preferred, because this term describes the mechanism much better: polymer molecules are separated according to their hydrodynamic volumes (which can be correlated with molar mass), with the larger size molecules exiting first followed by the smaller. Molar masses are determined either from a calibration or using molar mass sensitive detectors. In the case of copolymers, the knowledge of chemical composition along the MMD is required, which can be obtained from combinations of different concentration detectors. As the hydrodynamic volumes of different polymers are typically somewhat different, molecules with different chemical composition and different molar mass will be eluted in the same slice of the chromatogram. Obviously, a discrimination between such molecules requires a two‐dimensional separation, in which one dimension may be SEC, and the other one a chromatographic technique, which separates according to chemical composition rather than molar mass, such as liquid adsorption chromatography (LAC), liquid chromatography at the critical point of adsorption (often also called liquid chromatography under critical conditions, LCCC), supercritical fluid chromatography (SFC), temperature rising elution fractionation (TREF), etc. In the lower molar mass range, mass spectroscopy competes with SEC. The most frequently used technique is matrix‐assisted laser desorption/ionization time‐of‐flight mass spectroscopy (MALDI/TOF/MS), which cannot, however, provide quantitatively accurate MMDs. Due to its excellent resolution in molar mass, it can be combined with chromatographic techniques in order to increase the reliability of the analysis.
Size‐exclusion chromatography (SEC) is a standard technique for determining molar mass averages and molar mass distributions (MMDs) of polymers. Sometimes the termsgel permeation chromatography (GPC) or gel filtration chromatography (GFC) are also used, but SEC should be preferred, because this term describes the mechanism much better: polymer molecules are separated according to their hydrodynamic volumes (which can be correlated with molar mass), with the larger size molecules exiting first followed by the smaller. Molar masses are determined either from a calibration or using molar mass sensitive detectors. In the case of copolymers, the knowledge of chemical composition along the MMD is required, which can be obtained from combinations of different concentration detectors. As the hydrodynamic volumes of different polymers are typically somewhat different, molecules with different chemical composition and different molar mass will be eluted in the same slice of the chromatogram. Obviously, a discrimination between such molecules requires a two‐dimensional separation, in which one dimension may be SEC, and the other one a chromatographic technique, which separates according to chemical composition rather than molar mass, such as liquid adsorption chromatography (LAC), liquid chromatography at the critical point of adsorption (often also called liquid chromatography under critical conditions, LCCC), supercritical fluid chromatography (SFC), temperature rising elution fractionation (TREF), etc. In the lower molar mass range, mass spectroscopy competes with SEC. The most frequently used technique is matrix‐assisted laser desorption/ionization time‐of‐flight mass spectroscopy (MALDI/TOF/MS), which cannot, however, provide quantitatively accurate MMDs. Due to its excellent resolution in molar mass, it can be combined with chromatographic techniques in order to increase the reliability of the analysis.
This review covers fundamental developments and selected applications of SEC and related techniques abstracted by Chemical Abstracts and Medline from 1996 to 1997 inclusive and is a continuation of our previous review (A8). Suggestions are always welcome for improving coverage of topics.The authors gratefully acknowledge our respective companies and families for their support and assistance during the preparation of this review. We are especially thankful to Thomas C. Johns (DuPont) for the literature search strategies and Rebecca Pennington (DuPont) and Wanda Mayhew for their excellent typing skills. BOOKS, PROCEEDINGS, AND REVIEWSDuring this review period, only one book has been published dedicated to preparative SEC, with a focus on Sephadex LH-20 (A1). Conference proceedings on SEC and related techniques have been sponsored by the ACS Division of Polymeric Material Science and Engineering (A2), the International GPC Symposium (A3), the 10th Bratislava International Conference on Macromolecules (A4, A5), Rapra (A6), and the International Symposium on Polymer Analysis and Characterization (A7).Reviews on specific SEC topics and applications are covered in the appropriate sections of this article. The Selected Applications section lists specific reviews based on polymer type. Barth and co-workers (A8) presented comprehensive coverage of SEC literature from 1994 to 1995; the present review is a continuation of that format. General reviews on SEC can be found in refs A9 and A10. Machate (A11) discussed various chromatographic approaches for the characterization of coating resins, including SEC. Historical perspectives of SEC were presented by Porath (A12), who dealt with packings, and by Barth (A13) and Benoit (A14), who considered calibration approaches. Henry (A15) reviewed recent innovations in SEC and instrument design. Belenkii et al. (A16) described nonstandard methods based on SEC, such as critical chromatography, membrane chromatography, TLC, and microbore SEC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.