National Repository of Grey Literature 5 records found  Search took 0.01 seconds. 
Analysis of products of cardanol metathesis by HPLC-MS/MS method
Flenerová, Zuzana ; Čabala, Radomír (advisor) ; Vrkoslav, Vladimír (referee)
Cardanols are more and more used in the industry of polymers, resins, coatings, friction materials, etc. At right conditions, these lipid-like chemicals can undergo metathesis reaction. The main aim of the diploma thesis is an analysis of products of cardanol metathesis by HPLC-MS/MS. Standard 3,3'-hexadec-8-en-1,16-diyldiphenol, one of the main products of cardanol metathesis, was prepared for quantitative HPLC analysis. The standard was prepared in two steps. The first step was cardanol ethenolysis to give 3-(non-8-enyl)phenol. The second step was self-metathesis of 3-(non-8- enyl)phenol to give 3,3'-hexadec-8-en-1,16-diyldiphenol. The standard was characterised by HPLC/MS, MS/MS, EI-MS, UV/VIS, IR, Raman a NMR spectroscopy. The second part of the thesis is dedicated to the study of a mechanism of double-bond localization method in long chain hydrocarbons by acetonitrile APCI-MS. The formation of adducts [M + 55]+ , which are the key substances of this method, was studied using simple alkene models by MS and MS/MS. At the end, the structure and the mechanism of the formation of adducts [M + 55]+ were suggested. Key words: Cardanol, olefin metathesis, HPLC-MS, double-bond localization, APCI, acetonitrile
Determination of double bond position in wax esters by dimethyl disulfide derivatization and mass spectrometry
Háková, Martina ; Schwarzová, Karolina (advisor) ; Coufal, Pavel (referee)
Wax esters are substantial constituents of natural waxes, which can be found in many living organisms. Properties of lipids, including wax esters, may be significantly influenced by the position of double bond. In this diploma thesis the location of double bonds was determined by dimethyl disulfide (DMDS) derivatization followed by detection using tandem mass spectrometry with atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI). We managed to measure the APCI and ESI MS/MS spectra of 8 different wax esters with different position of double bond. Diagnostic ions determining double bond position were identified. This method could be used in HPLC/MS analysis of wax esters, which cannot be analyzed by GC/MS. It was shown that the DMDS derivatization reaction and mass detection with APCI ionization is also suitable for locating double bonds in alkenes.
Analysis of products of cardanol metathesis by HPLC-MS/MS method
Flenerová, Zuzana ; Čabala, Radomír (advisor) ; Vrkoslav, Vladimír (referee)
Cardanols are more and more used in the industry of polymers, resins, coatings, friction materials, etc. At right conditions, these lipid-like chemicals can undergo metathesis reaction. The main aim of the diploma thesis is an analysis of products of cardanol metathesis by HPLC-MS/MS. Standard 3,3'-hexadec-8-en-1,16-diyldiphenol, one of the main products of cardanol metathesis, was prepared for quantitative HPLC analysis. The standard was prepared in two steps. The first step was cardanol ethenolysis to give 3-(non-8-enyl)phenol. The second step was self-metathesis of 3-(non-8- enyl)phenol to give 3,3'-hexadec-8-en-1,16-diyldiphenol. The standard was characterised by HPLC/MS, MS/MS, EI-MS, UV/VIS, IR, Raman a NMR spectroscopy. The second part of the thesis is dedicated to the study of a mechanism of double-bond localization method in long chain hydrocarbons by acetonitrile APCI-MS. The formation of adducts [M + 55]+ , which are the key substances of this method, was studied using simple alkene models by MS and MS/MS. At the end, the structure and the mechanism of the formation of adducts [M + 55]+ were suggested. Key words: Cardanol, olefin metathesis, HPLC-MS, double-bond localization, APCI, acetonitrile
Determination of double bond position in wax esters by dimethyl disulfide derivatization and mass spectrometry
Háková, Martina ; Schwarzová, Karolina (advisor) ; Coufal, Pavel (referee)
Wax esters are substantial constituents of natural waxes, which can be found in many living organisms. Properties of lipids, including wax esters, may be significantly influenced by the position of double bond. In this diploma thesis the location of double bonds was determined by dimethyl disulfide (DMDS) derivatization followed by detection using tandem mass spectrometry with atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI). We managed to measure the APCI and ESI MS/MS spectra of 8 different wax esters with different position of double bond. Diagnostic ions determining double bond position were identified. This method could be used in HPLC/MS analysis of wax esters, which cannot be analyzed by GC/MS. It was shown that the DMDS derivatization reaction and mass detection with APCI ionization is also suitable for locating double bonds in alkenes.

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