uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Discovery of invisible extra fronts in single-component frontal analysis in liquid chromatography
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Surface Biotechnology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Surface Biotechnology.
2006 (English)In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1114, no 1, p. 53-61Article in journal (Refereed) Published
Abstract [en]

Frontal analysis (FA) is often used in the “staircase mode”, in which the solute concentration in the eluent increases stepwise. We demonstrate here in the single-component case, that all eluted breakthrough curves (fronts) for the second and subsequent steps consist solely of displaced plateau molecules. The newly introduced molecules (i.e., the introduced mass) instead elute later, in a breakthrough front hidden from detection, i.e., the mass front. These effects were studied using experimentally verified numerical calculations, the mass fronts being visualized using an enantiomer pair in an achiral separation system. Notably, the mass front displays no self-sharpening effects, even under strongly nonlinear conditions. Instead, the front is sigmoidal in shape.

Place, publisher, year, edition, pages
2006. Vol. 1114, no 1, p. 53-61
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-96954DOI: 10.1016/j.chroma.2006.02.027OAI: oai:DiVA.org:uu-96954DiVA, id: diva2:171702
Available from: 2008-04-04 Created: 2008-04-04 Last updated: 2018-01-23Bibliographically approved
In thesis
1. Development of Methods for Phase System Characterization in Liquid Chromatography
Open this publication in new window or tab >>Development of Methods for Phase System Characterization in Liquid Chromatography
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The aim of this thesis is first and foremost to improve the fundamental knowledge of nonlinear and preparative separation theory by focusing on some of the remaining “white spots” on the theoretical chromatographic map. Secondly, the acquired knowledge is used to develop, validate and execute new methods for phase characterization in liquid chromatography. The methodology used in this thesis is a combination of experiments, fundamental nonlinear theory and systematic computer simulations.

A fundamental knowledge of the molecular interactions between the compounds to be separated and the separation media requires the determination of adsorption isotherms over a broad concentration range to give a complete picture of all interactions in the separation system - weak as well as strong. In addition, such adsorption data is essential for optimization in preparative chromatography.

For the first time, it has been experimentally shown that the injected molecules are not present in the detected peak when a small excess of molecules are injected into a chromatographic system equilibrated with a constant stream of identical molecules. Several experimental procedures for this method were developed such as (i) the optimal injection strategy and (ii) different labeling methods for visualizing the injected molecules. Remarkable phenomena in the single-component case, such as invisible peak deformation and deformed (invisible) frontal chromatograms, are reported, investigated, and explained. This phenomenon has asides from its future practical implementation, also a large didactic value.

The accuracy of the ECP method is experimentally improved, and used to characterize the separation of protolytic compounds at different pH on modern commercially available silica and hybrid silica column packing materials. That investigation enables us to answer why basic compounds give a much more compact preparative peak profile at pH 11 than they yields at lower pH.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2008. p. 69
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 416
Keyword
Analytical chemistry, Liquid chromatography, Adsorption isotherms, Adsorption energy distribution, Tracer pulse method, Elution by characteristic points, Peak deformation, Validation, Hybrid column material, Alkaline separation, Injection-profiles, Analytisk kemi
Identifiers
urn:nbn:se:uu:diva-8597 (URN)978-91-554-7145-3 (ISBN)
Public defence
2008-04-25, B41, BMC, Husargatan 3, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2008-04-04 Created: 2008-04-04 Last updated: 2009-03-20Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Samuelsson, JörgenFornstedt, Torgny

Search in DiVA

By author/editor
Samuelsson, JörgenFornstedt, Torgny
By organisation
Surface BiotechnologySurface Biotechnology
In the same journal
Journal of Chromatography A
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 536 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf