Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • 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
Continuous full filling capillary electrochromatography-electrospraying chromatographic nanoparticles
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
Nanosep, Lund.
Show others and affiliations
2011 (English)In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 32, no 2, p. 261-267Article in journal (Refereed) Published
Abstract [en]

The influence of instrumental parameters affecting the ionization in continuous full filling capillary electrochromatography/electrospray ionization mass spectrometry (CFF-CEC/ESI-MS) was investigated. The investigated parameters were the BGE and sheath liquid ion strength and organic modifier content, the nebulizer gas pressure, and the concentration of nanoparticles in the BGE. It was found that the nebulizer pressure had the largest influence on the separation efficiency and apparent retention. It was shown that even the lowest pressure investigated was sufficient to guide the nanoparticle flow away from the mass spectrometer inlet. A nebulizer pressure of 5 psi was found to be optimal; increasing the pressure significantly decreased the separation efficiency due to the generation of a hydrodynamic flow. Generally, the ion strength of both the BGE and the sheath liquid were found to have very moderate effects on the separation of a homologous series of dialkyl phthalates, whereas the ionization efficiency was found to be unaffected by the nanoparticles and the separation efficiency was found to increase with increasing concentrations up to 3.8 mg/mL, whereafter it was observed to drop. The optimized method was linear over a wide concentration range and presented LOD and LOQ more than threefold lower than those previously reported using CFF-CEC/ESI-MS.

Place, publisher, year, edition, pages
2011. Vol. 32, no 2, p. 261-267
Keyword [en]
Continuous full filling capillary electrochromatography, Nanoparticles, Nebulizing gas pressure, Pseudostationary phase, Sheath liquid
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-145492DOI: 10.1002/elps.201000261ISI: 000287156700009PubMedID: 21254124OAI: oai:DiVA.org:uu-145492DiVA, id: diva2:396294
Funder
Swedish Research Council
Available from: 2011-02-09 Created: 2011-02-09 Last updated: 2017-12-11Bibliographically approved
In thesis
1. Nanoparticles in capillary electrophoresis: what are the benefits?
Open this publication in new window or tab >>Nanoparticles in capillary electrophoresis: what are the benefits?
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Capillary electrophoresis is a technique that separate compounds based on charge and size. During the last two decades capillary electrophoresis (CE) and mass spectrometry (MS) has gained in interest, become more robust to use and able to separate neutral analytes. The separation of neutral analytes was first achieved with packed columns, but several disadvantages can be obtained with a stationary phase and the method of packing capillaries. Therefore, pseudostationary phases became a good alternative. The risk of clogging, memory effects and lower efficiency could be minimized with pseudophases. However, since mass spectrometry has become the most important analytical detector, and play a key role in the search for biomarkers in clinical applications, it is important that CE can successfully be combined with MS. To obtain this hyphenation several types of interfaces for the vital ion source exist. In paper I an atmospheric pressure photoionization interface was investigated in order to accomplish an improved detection sensitivity. The knowledge attained with this type of interface could then be transferred to the one used in paper II, the electrospray ionization interface (ESI), where the use of a MS friendly nanoparticle based pseudostationary phase was investigated. Both studies showed that it is still possible to improve the separation technique and modify the ion source in order to improve the detection sensitivity for capillary electrophoresis hyphenated with mass spectrometry.

Place, publisher, year, edition, pages
Uppsala: Institutionen för fysikalisk och analytisk kemi, Uppsala universitet, 2011
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-147008 (URN)
Supervisors
Available from: 2011-02-24 Created: 2011-02-23 Last updated: 2011-03-16Bibliographically approved
2. Interfacing Complementary Separation Techniques with Mass Spectrometry Utilizing Electrophoresis, Nanoparticles, and Functionalized Magnetic Beads
Open this publication in new window or tab >>Interfacing Complementary Separation Techniques with Mass Spectrometry Utilizing Electrophoresis, Nanoparticles, and Functionalized Magnetic Beads
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Capillary electrophoresis (CE) has during the last two decades become more robust and been able to separate neutral analytes without compromising the downstream detection. An interesting aspect in CE compared to more commonly used high-performance liquid chromatography is the orthogonal separation mechanism provided by CE. Compounds are separated based on charge and size with extremely high separation efficiencies. However, since mass spectrometry (MS) has become one of the most important analytical detectors and play a key role for pharmaceutical- and in clinical applications it is of major importance that the two techniques successfully can be combined without any compromises. Improvements in existing ion sources must be made in order to fully take advantage of the potential in capillary electrophoresis and mass spectrometry. One way is to miniaturize the ion source (paper I) in order to make it more compatible with the smaller liquid volumes and lower flow rates in CE. Despite these improvements challenges such as low sample concentrations, non-separated peaks, unspecific losses, and poor ionization still remain, and are addressed in this doctoral thesis.

Separation of neutral analytes has previously been achieved with packed columns but with several disadvantages. Therefore, MS-compatible pseudostationary phases in the form of nanoparticles (paper II) are an interesting alternative with its minimized risk of clogging, reduced memory effects and better separation efficiencies. Particles or beads have also shown to be of importance when reducing the dynamic range in complex samples. By creating functionalized magnetic beads (paper III), complex samples such as human plasma can be fractionated in the manner that low molecular weight proteins are selectively enriched. Despite fractionation and enrichment of analytes of interest (paper IV) the ionization suppression could lead to biased sensitivity, increased baseline, retention variations and chromatographic distortion. Therefore the separation, as well as the ionization, is of major importance. For instance, in order to separate and detect monoclonal antibodies, which are an upcoming class of biotherapeutic drugs, the choice of capillary temperature and sheath liquid composition must be considered due to its major influence on charge state, peak intensity and memory effects (paper V).

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2012. p. 63
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 993
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:uu:diva-183666 (URN)978-91-554-8529-0 (ISBN)
Public defence
2012-12-14, B42, Husargatan 3, Uppsala, 10:15 (English)
Opponent
Supervisors
Available from: 2012-11-22 Created: 2012-10-31 Last updated: 2013-02-11Bibliographically approved

Open Access in DiVA

fulltext(14193 kB)790 downloads
File information
File name FULLTEXT01.pdfFile size 14193 kBChecksum SHA-512
afd34b2c2ec1cccccdc2695cb11936dd8ce77a4621ce32c4b784f1885eced1260c8380a4c94b6fed6f8e9576e1f2b38a12058ff7851a85dc6bc7bac48090f3d9
Type fulltextMimetype application/pdf

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Malmström, DavidAxén, JakobBergquist, Jonas
By organisation
Analytical Chemistry
In the same journal
Electrophoresis
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 790 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 960 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • 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