Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Improved matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry of carboxymethyl cellulose
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.ORCID iD: 0000-0002-5394-7850
2006 (English)In: Rapid Communications in Mass Spectrometry, ISSN 0951-4198, E-ISSN 1097-0231, Vol. 20, no 24, 3693-3698 p.Article in journal (Refereed) Published
Abstract [en]

A refined sample preparation procedure for matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS) was developed for the evaluation of the degree of substitution (DS) in partially depolymerised carboxymethyl cellulose (CMC). By adding ammonium sulphate to the sample mixture prior to the analysis, good quality mass spectra could be acquired. The usual time-consuming search for 'sweet-spots' at the crystalline rim of the MALDI target spot was also avoided. This quality improvement made it possible to investigate whether various positions on the target spot generated mass spectra in which the measured DS varied. The accuracy and reproducibility of the sample preparation procedure were tested by applying it on three commercial CMCs. The study shows that the DS values that were calculated from the spectra acquired from the centre region of the MALDI target spot were in better agreement with the DS provided by the supplier than were the values obtained from the large crystals at the target spot rim. This observation could be one reasonable explanation for the higher DS values reported in other publications. By applying our refined MALDI sample preparation procedure DS values that were in good agreement with the values provided by the manufacturer could be obtained. This indicates that MALDI-TOFMS of partially depolyrnerised CMCs can be used for an estimation of the DS as a complement to the more established methods, e.g. NMR, titrimetry, and chromatographic techniques.

Place, publisher, year, edition, pages
2006. Vol. 20, no 24, 3693-3698 p.
Keyword [en]
desorption, oligonucleotides, chromatography, substituents, ethers, acid
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-7104DOI: 10.1002/rcm.2786ISI: 000242936400011Scopus ID: 2-s2.0-33845565989OAI: oai:DiVA.org:kth-7104DiVA: diva2:12016
Note
QC 20100720Available from: 2007-05-15 Created: 2007-05-15 Last updated: 2011-09-05Bibliographically approved
In thesis
1. New Mass Spectrometric Methods for Structure Analysis of Carboxymethyl Cellulose
Open this publication in new window or tab >>New Mass Spectrometric Methods for Structure Analysis of Carboxymethyl Cellulose
2008 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Carboxymethyl cellulose (CMC) is a cellulose derivative, made from cellulose by introduction of carboxymethyl groups along the molecules. The properties of CMC are affected by several parameters where the molar mass and molar mass distribution, degree of substitution (DS) and the distribution pattern along, and between, the cellulose molecules are the most prominent.

In the present thesis we have investigated the use of various mass spectrometric techniques, such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and electrospray ionization MS (ESI-MS), for characterization of the chemical structure of CMC. We here present a refined sample preparation procedure for MALDI that greatly facilitates the spectrum acquisition and improves the quality of the mass spectrum when analyzing partially hydrolyzed CMC. The refined method allows for estimation of the DS in CMC samples as a complement to more expensive and laborious methods. We also show that by combining MALDI-TOFMS with selective hydrolysis, by purified endoglucanase, and size-exclusion chromatography (SEC) it is possible to differentiate between CMCs of similar monomer composition but differences in the substitution pattern. Our findings show that the CMC containing longer non-substituted cellulose segments along the polymer backbone also displayed the highest intermolecular interactions in solution, as measured by rheometry.

In order to take full advantage of the selective hydrolysis, provided by purified endoglucanases, more information regarding their selectivity on CMC must be investigated. We therefore present methods where chemical sample preparation of the oligomeric enzyme products is performed in order to facilitate the chemical structure characterization by ESI-MS/MS and liquid chromatography MS (LC-MS). These methods provides valuable information regarding the substituent distribution along the oligomeric enzyme products, and thereby gives indications regarding the selectivity of the endoglucanases on CMC substrates. From our finding we are able to present interesting information regarding the selectivity of four endoglucanases (Cel7B, Cel5A, Cel45A and Cel74A) from the filamentous fungus Trichoderma reesei and provide plausible explanations to their apparent differences in selectivity on CMC.

Abstract [sv]

Karboximetylcellulosa (CMC) är ett kommersiellt viktigt cellulosaderivat som bl.a. används som förtjockningsmedel och bindemedel i livsmedel och läkemedelsformuleringar. CMC framställs från cellulosa genom kemisk modifiering där karboximetyl grupper introduceras längs cellulosamolekylerna. Modifieringen ger materialet nya egenskaper, bl. a.  vattenlöslighet, vilket öppnar för nya användningsområden.  Egenskaperna hos CMC påverkas bl. a. av parametrar som molekylvikt och molekylviktsfördelning, substitutionsgraden (DS) och fördelning av substituenter över, och mellan, cellulosakedjorna.

I den presenterade avhandlingen så undersöker vi möjligheterna av att använda olika mass spektrometriska metoder, så som matris-assisterad laser-desorption/joniserings löptids-masspektrometri (MALDI-TOFMS) och elektrospray-jonisering masspektrometri (ESI-MS) för karaktärisering av den kemiska strukturen i CMC. Vi presenterar en förbättrad provprepareringsmetod för MALDI som både förenklar insamlingen av, och förbättrar kvaliteten på, masspektra från delvis hydrolyserad CMC. Den förbättrade metoden möjliggör även en estimering av DS-värdet i de intakta CMC proverna, vilket innebär att denna metod är ett komplement till dyrare och mer arbetskrävande tekniker. Vi visar också att MALDI-TOFMS, i kombination med enzymatisk nedbrytning, och andra sofistikerade analysmetoder (t ex storleksuteslutningskromatografi (SEC)), kan användas för att särskilja CMC-prover med liknande monomersammansättning men med olika substitutionsmönster. Resultaten från studien visar att CMC-prov innehållande längre osubstituerade cellulosasegment längs molekylerna, påvisar högre grad av intermolekylära interaktioner i lösning, mätt med reometri. 

För att kunna utnyttja den selektiva hydrolysen från enzymatisk nedbrytning på bästa sätt så bör selektiviteten på de nyttjade enzymerna undersökas. Vi presenterar därför metoder där de bildade oligomererna från den enzymatiska nedbrytningen genomgår en kemisk provpreparering, för att förenkla efterföljande analyser med ESI-MS/MS och vätskekromatografi MS (LC-MS). Med dessa metoder kan man undersöka substitutions positionerna på oligomererna och därigenom få indikationer på enzymets selektivitet mot CMC. Från våra resultat så kan vi presentera intressant information gällande fyra olika endoglukanaser (Cel7B, Cel5A, Cel45A and Cel74A)  från den fintrådiga svampen Trichoderma reesei och ge möjliga förklaringar till deras påvisade skillnader i selektivitet mot CMC.

Place, publisher, year, edition, pages
Stockholm: KTH, 2008. 60 p.
Series
Trita-CHE-Report, ISSN 1654-1081 ; 2008:68
Keyword
carboxymethyl cellulose, substituent distribution, rheology, enzyme hydrolysis, cellulase, permethylation, liquid chromatography, MALDI, ESI, mass spectrometry
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-9438 (URN)978-91-7415-162-6 (ISBN)
Public defence
2008-11-28, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note
QC 20100720Available from: 2008-11-06 Created: 2008-11-03 Last updated: 2010-07-20Bibliographically approved
2. Characterization of carboxymethyl cellulose by MALDI-TOFMS
Open this publication in new window or tab >>Characterization of carboxymethyl cellulose by MALDI-TOFMS
2007 (English)Licentiate thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2007. 32 p.
Series
Trita-CHE-Report, ISSN 1654-1081 ; 2007:28
National Category
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-38989 (URN)978-91-7178-672-2 (ISBN)
Presentation
2007-05-31, Sal E3, Osquars backe 14, KTH, Stockholm, 10:00
Note
QC 20110905Available from: 2011-09-05 Created: 2011-09-05 Last updated: 2011-09-05Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Karlsson, Sigbritt

Search in DiVA

By author/editor
Enebro, JonasKarlsson, Sigbritt
By organisation
Fibre and Polymer Technology
In the same journal
Rapid Communications in Mass Spectrometry
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 271 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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