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LDI-MS strategies for analysis of polymer degradation products, additives and drugs
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The advancement of mass spectrometry (MS) has been and continues to be a prominent analytical technique for highly accurate determination of analytes. The goal of this thesis was to develop new laser desorption ionization-mass spectrometric (LDI-MS) methods for analysis of polymer degradation products, additives and drugs. Modifications in the sample preparation were evaluated in the presence and absence of surface assisting materials. Various nanoparticles were evaluated as effective absorbents for energy transfer in the LDI procedure of the small molecules.

In paper I and II, LDI-MS methods were developed for following the progression of chemical reactions. First, the procedure to optimize microwave assisted hydrothermal degradation products of cellulose were analyzed; second, the synthesis of glucose hexanoate ester plasticizers was monitored as a function of reaction time. The LDI-MS method provided rapid detection for the elucidation of the chemical products and their relative ratios. In contrast, the electrospray ionization-mass spectrometry (ESI-MS) analysis produced a noisy spectrum primarily containing peaks from salt clusters. A surface assisted laser desorption ionization-mass spectrometry (SALDI-MS) method was developed in paper III enabling the identification of poly(e-caprolactone) and its degradation products by using nanoparticles as the substrate. Similar analysis by matrix assisted laser desorption ionization-mass spectrometry (MALDI-MS) was not as successful due to convolution of the analyte peaks with clusters released from the matrix. ESI-MS analysis verified the SALDI-MS method as comparable degradation product patterns were observed. Furthermore, the possibility of using polylactide based nanocomposites as surfaces in the analysis of drugs was evaluated in paper IV. An advantage was the ease of handling compared to the use of free nanoparticles. Paper V introduces the potential of direct examination of oxygen plasma modified parylene C surfaces by a LDI-MS methodology. 

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. , 57 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2014:33
Keyword [en]
laser desorption ionization-mass spectrometry (LDI-MS), surface, polymer degradation products, additive, drugs, nanoparticles, nanocomposites
National Category
Polymer Technologies
Research subject
Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-152647ISBN: 978-91-7595-233-8 (print)OAI: oai:DiVA.org:kth-152647DiVA: diva2:750831
Public defence
2014-10-24, Kollegiesalen, Brinellvägen 8, KTH, Stockholm, 09:00 (English)
Opponent
Supervisors
Note

QC  20141002

Available from: 2014-10-02 Created: 2014-09-30 Last updated: 2014-10-02Bibliographically approved
List of papers
1. Chemo-selective high yield microwave assisted reaction turns cellulose to green chemicals
Open this publication in new window or tab >>Chemo-selective high yield microwave assisted reaction turns cellulose to green chemicals
2014 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 112, 448-457 p.Article in journal (Refereed) Published
Abstract [en]

Exceptionally high cellulose liquefaction yields, up to 87% as calculated from the amount of solid residue, were obtained under mild conditions by utilizing the synergistic effect of microwave radiation and acid catalysis. The effect of processing conditions on degradation products was fingerprinted by rapid laser desorption ionization-mass spectrometry (LDI-MS) method. The reaction was chemo-tunable, enabling production of glucose (Glc) or levulinic acid (LeA) at significantly high selectivity and yields, the relative molar yields being up to 50 and 69%, respectively. A turning point from pure depolymerization to glucose to further degradation to levulinic acid and formic acid was observed at approximately 50% liquefaction or above 140 degrees C. This was accompanied by the formation of small amounts of solid spherical carbonized residues. The reaction was monitored by multiple analytical techniques. The high yields were connected to the ability of the process to break the strong secondary interactions in cellulose. The developed method has great potential for future production of green platform chemicals.

Keyword
Cellulose, Liquefaction, Glucose, Levulinic acid, Hydrothermal degradation, Carbon sphere
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-152816 (URN)10.1016/j.carbpol.2014.06.011 (DOI)000341464600059 ()2-s2.0-84903555052 (Scopus ID)
Note

QC 20141002

Available from: 2014-10-02 Created: 2014-10-02 Last updated: 2017-12-05Bibliographically approved
2. Glucose esters as biobased PVC plasticizers
Open this publication in new window or tab >>Glucose esters as biobased PVC plasticizers
2014 (English)In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 58, 34-40 p.Article in journal (Refereed) Published
Abstract [en]

Utilization of glucose, produced by liquefaction of cellulose or other abundant biomass sources, as raw material for production of green plasticizers would offer an attractive alternative to traditional phthalate plasticizers. Three glucose hexanoate esters (GHs) were synthesized by one-step reaction and evaluated as green plasticizers for poly(vinyl chloride) (PVC). The esterification was carried out for three different time periods to obtain plasticizers with different number of hexanoate groups, as the degree of substitution could influence the miscibility between PVC and GHs. A fast and powerful laser desorption ionization-mass spectrometry (LDI-MS) method was developed to obtain molecular level structural information of the plasticizer structures. All the GHs showed good miscibility with PVC and the GH blends exhibited better mechanical properties, in the form of higher strain at break and lower modulus, as compared to glucose pentaacetate (GPA) and sucrose octaacetate (SOA) blends that were studied in comparison. Altogether the results indicate that the synthesized glucose esters have large potential as green PVC plasticizers and they could be a promising option to overcome the environmental problems caused by phthalate plasticizers.

Keyword
Biomass; Chlorine compounds; Esterification; Esters; Glucose; Ionization; Mass spectrometry; Plasticizers; Reinforced plastics; Solubility; Solvents; Strain, Degree of substitution; Environmental problems; Glucose ester; Green plasticizers; Laser desorption; Phthalate plasticizers; Structural information; Sucrose octaacetate, Polyvinyl chlorides
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-152695 (URN)10.1016/j.eurpolymj.2014.06.008 (DOI)000341675400004 ()2-s2.0-84903942738 (Scopus ID)
Note

QC 20141002

Available from: 2014-10-02 Created: 2014-10-01 Last updated: 2017-12-05Bibliographically approved
3. Surface Assisted Laser Desorption Ionization-Mass Spectrometry (SALDI-MS) for Analysis of Polyester Degradation Products
Open this publication in new window or tab >>Surface Assisted Laser Desorption Ionization-Mass Spectrometry (SALDI-MS) for Analysis of Polyester Degradation Products
2012 (English)In: Journal of the American Society for Mass Spectrometry, ISSN 1044-0305, E-ISSN 1879-1123, Vol. 23, no 6, 1071-1076 p.Article in journal (Refereed) Published
Abstract [en]

Novel surface assisted laser desorption ionization-mass spectrometry (SALDI-MS) method was developed for rapid analysis of low molecular mass polyesters and their degradation products by laser desorption ionization-mass spectrometry. Three polycaprolactone materials were analyzed by the developed method before and after hydrolytic degradation. The signal-to-noise values obtained by SALDI-MS were 20-100 times higher compared with the ones obtained by using traditional MALDI-MS matrices. A clean background at low mass range and higher resolution was obtained by SALDI-MS. Different nanoparticle, cationizing agent, and solvent combinations were evaluated. Halloysite nanoclay and magnesium hydroxide showed the best potential as SALDI surfaces. The SALDI-MS spectrum of the polyester hydrolysis products was verified by ESI-MS. The developed SALDI-MS method possesses several advantages over existing methods for similar analyses.

Keyword
surface assisted laser desorption ionization-mass spectrometry (SALDI-MS), polyester, polycaprolactone, degradation, nanoparticles
National Category
Polymer Technologies Polymer Chemistry Analytical Chemistry
Identifiers
urn:nbn:se:kth:diva-91483 (URN)10.1007/s13361-012-0360-8 (DOI)000303685800010 ()2-s2.0-84864866736 (Scopus ID)
Note

Updated from submitted to published. QC 20120607

Available from: 2012-03-16 Created: 2012-03-16 Last updated: 2017-12-07Bibliographically approved
4. Nanocomposites as novel surfaces for laser desorption ionization mass spectrometry
Open this publication in new window or tab >>Nanocomposites as novel surfaces for laser desorption ionization mass spectrometry
2011 (English)In: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 3, no 1, 192-197 p.Article in journal (Refereed) Published
Abstract [en]

The possibility to utilize nanocomposite films as easy-to-handle surfaces for surface assisted laser desorption ionization-mass spectrometry (SALDI-MS) of small molecules, such as pharmaceutical compounds, was evaluated. The signal-to-noise values of acebutolol, propranolol and carbamazepine obtained on the nanocomposite surfaces were higher than the values obtained on plain PLA surface showing that the nanoparticles participate in the ionization/desorption process even when they are immobilized in the polymer matrix. The advantages of nanocomposite films compared to the free nanoparticles used in earlier studies are the ease of handling and reduction of instrument contamination since the particles are immobilized into the polymer matrix. Eight inorganic nanoparticles, titanium dioxide, silicon dioxide, magnesium oxide, hydroxyapatite, montmorillonite nanoclay, halloysite nanoclay, silicon nitride and graphitized carbon black at different concentrations were solution casted to films with polylactide (PLA). There were large differences in signal intensities depending on the type of drug, type of nanoparticle and the concentration of nanoparticles. Polylactide with 10% titanium oxide or 10% silicon nitride functioned best as SALDI-MS surfaces. The limit of detection (LOD) for the study was ranging from 1.7 ppm up to 56.3 ppm and the signal to noise relative standard deviations for the surface containing 10% silicon nitride was approximately 20-30%. Scanning electron microscopy demonstrated in most cases a good distribution of the nanoparticles in the polymer matrix and contact angle measurements showed increasing hydrophobicity when the nanoparticle concentration was increased, which could influence the desorption and ionization. Overall, the results show that nanocomposite films have potential as surfaces for SALDI-MS analysis of small molecules.

Keyword
SMALL-MOLECULE ANALYSIS, SALDI-MS, ORGANIC-COMPOUNDS, MATRIX, NANOPARTICLES, PEPTIDES, PROTEINS
National Category
Polymer Technologies Polymer Chemistry Analytical Chemistry
Identifiers
urn:nbn:se:kth:diva-31390 (URN)10.1039/c0ay00531b (DOI)000287294200027 ()2-s2.0-79952965109 (Scopus ID)
Note
QC 20110314Available from: 2011-03-14 Created: 2011-03-14 Last updated: 2017-12-11Bibliographically approved
5. LDI-MS examination of oxygen plasma modified polymer for designing tailored implant biointerfaces
Open this publication in new window or tab >>LDI-MS examination of oxygen plasma modified polymer for designing tailored implant biointerfaces
Show others...
2014 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 50, 26240-26243 p.Article in journal (Refereed) Published
Abstract [en]

A versatile polymer coating for biomaterials was fabricated by the mild oxygen plasma treatment of Chemical Vapour Deposited (CVD) parylene C. The surface properties were tailored while the excellent protective properties of the bulk were preserved. The species, formed due to the plasma functionalisation, were fingerprinted by a novel Laser Desorption/Ionisation-Mass Spectrometry (LDI-MS) method. Improved osteosarcoma cells (line MG-63) attachment and viability on a modified surface were demonstrated.

Keyword
Parylene C, Surface, Biomaterials, Wettability, Behavior, Alloys
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:kth:diva-148653 (URN)10.1039/c4ra02656j (DOI)000338434800031 ()2-s2.0-84903288600 (Scopus ID)
Note

QC 20140811

Available from: 2014-08-11 Created: 2014-08-11 Last updated: 2017-12-05Bibliographically approved

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