scholarly journals Ring-opening polymerization of β-butyrolactone in the presence of alkali metal salts: investigation of initiation course and determination of polymers structure by MALDI-TOF mass spectrometry

2018 ◽  
Vol 76 (10) ◽  
pp. 4951-4966 ◽  
Author(s):  
Zbigniew Grobelny ◽  
Sylwia Golba ◽  
Justyna Jurek-Suliga
Keyword(s):  
Mass Spectrometry ◽  
Alkali Metal ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
Maldi Tof Mass Spectrometry ◽  
Maldi Tof

scholarly journals Ring-opening polymerization of monosubstituted oxiranes in the presence of potassium hydride: determination of initiation course and structure of macromolecules by MALDI-TOF mass spectrometry

2019 ◽  
Vol 26 (12) ◽  
Author(s):  
Zbigniew Grobelny ◽  
Justyna Jurek-Suliga ◽  
Sylwia Golba
Keyword(s):  
Mass Spectrometry ◽  
Ring Opening ◽  
Glycidyl Ether ◽  
Ring Opening Polymerization ◽  
Size Exclusion ◽  
Oxirane Ring ◽  
Maldi Tof ◽  
Glycidyl Ethers ◽  
Initiation Step ◽  
Potassium Hydride

AbstractSeveral monosubstituted oxiranes were polymerized with suspension of potassium hydride (KH) in tetrahydrofuran (THF) at room temperature. This heterogeneous process resulted in polyethers with various starting groups depending on the kind of monomer. The macromolecules formed in ring-opening polymerization of monosubstituted oxiranes were analyzed by Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS). It was stated, that initiation of propylene oxide (PO) polymerization with KH proceeded via three ways, i.e. cleavage of oxirane ring in the β-position, monomer deprotonation and deoxygenation. Potassium isopropoxide, potassium allyloxide and potassium hydroxide were the real initiators. The main reactions, which occur in the initiation step, depend on the type of monomer used. In the case of allyl glycidyl ether (AGE) and phenyl glycidyl ether (PGE) deprotonation of the monomer did not occur. During initiation of glycidyl ethers oxirane ring was opened and also linear ether bond between glycidyl group and oxygen atom was cleaved under influence of KH. Interestingly, formation of new kinds of macromolecules was observed in the systems containing glycidyl ethers, which do not possess mers of the monomers used. Mechanisms of the studied processes were presented and discussed. Carbon-13 Nuclear Magnetic Resonance (13C NMR) was used as supporting technique for analysis of the obtained polymers. Number average molar masses of the polymers (Mn) determined by Size Exclusion Chromatography (SEC) were about two times higher than calculated ones. It indicated that half of used KH did not take part in the initiation step.

Qualitative determination of early Maillard-products by MALDI-TOF mass spectrometry peptide mapping

2002 ◽  
Vol 215 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Thomas Kislinger ◽  
Andreas Humeny ◽  
Silke Seeber ◽  
Cord-Michael Becker ◽  
Monika Pischetsrieder
Keyword(s):  
Mass Spectrometry ◽  
Peptide Mapping ◽  
Maldi Tof Mass Spectrometry ◽  
Maldi Tof ◽  
Maillard Products ◽  
Qualitative Determination

Determination of sensitivity of microorganisms of the Klebsiella genus to antimicrobial drugs by the MALDI-TOF MS method

Bacteriology ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 8-13
Author(s):  
A.A. Samoilova ◽  
◽  
I.V. Likhachev ◽  
E.V. Zueva ◽  
E.V. Rogacheva ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Antibiotic Resistance ◽  
Mass Spectra ◽  
Antimicrobial Agents ◽  
Antimicrobial Drugs ◽  
Maldi Tof Mass Spectrometry ◽  
Maldi Tof ◽  
Resistance Markers ◽  
Klebsiella Spp

Actual microbiological diagnostics of infections caused by Klebsiella spp. should include isolation of the strain, its identification and fastest possible determination of the pathogen susceptibility to antimicrobial agents. We evaluated the prospects of using MALDI-TOF mass spectrometry to determine the susceptibility of Klebsiella spp. strains to antimicrobial agents. According to the results of mass spectrometry Klebsiella spp. strains analysis, we carried out cluster analysis by the UPGMA method based on mass spectra and data on the susceptibility of the studied strains to antimicrobial agents, and then studied the obtained dendrograms. We identified the areas with the highest probability of the location of antibiotic resistance markers by comparing the mass spectra of susceptible and resistant microorganisms at different concentrations of antimicrobial agents. Thus, using MALDI-TOF mass spectrometry, a new direction in assessing the susceptibility of Klebsiella spp. to antimicrobial agents can be formed. Key words: antibiotic resistance, Klebsiella spp., MALDI-TOF mass spectrometry

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