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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
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Targeted analysis and metabolism of fatty acids in mice and humans
Oseeva, Marina ; Kuda, Ondřej (advisor) ; Cahová, Monika (referee) ; Vrkoslav, Vladimír (referee)
Widespread sedentary lifestyle and unhealthy eating habits in the last few decades have resulted in a dramatic increase of the number of people affected by obesity, type 2 diabetes, and cardiovascular diseases. The study of these pathological conditions revealed that impaired metabolism often causes these disorders. Lipid metabolism research has contributed significantly to determining mechanisms underlying metabolic disorders. Omega-3 fatty acids are an interesting target for lipidomics studies because they were shown to lower risk of cardiovascular diseases and are hypothesized to regulate lipid metabolism. In this work, I optimized lipid extraction and chemical modification methods for analysis of fatty acids profile of tissue samples and biofluids using comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GCxGC-MS). At first, I evaluated the relative amount of omega-3 fatty acids in red blood cells (Omega-3 index) of people living in Czech Republic in either the capital city (n=476) or the rural region (n=388). For this large-scale project, I extracted phospholipids from red blood cell (RBC) membranes, transesterified them into fatty acid methyl esters (FAMEs), and measured their profile by GCxGC-MS. The mean Omega-3 index was 3.56 mol % and I detected no significant...
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Localization of double and triple donds positions in fatty acids methylesters by HPLC/APCI-MS2
Horká, Petra ; Vrkoslav, Vladimír ; Cvačka, Josef
Poloha a počet dvojných vazeb v alifatickém řetězci ovlivňuje fyzikální, chemické a biologické vlastnosti lipidů, avšak jednoznačné určení poloh těchto násobných vazeb je problematické. V roce 2012 byla publikována metoda kapalinové chromatografie s chemickou ionizací za atmosférického tlaku s hmotnostní detekcí (HPLC/APCI-MS) [1] vhodná pro analýzu polohy dvojných vazeb využívající tvorby molekulových aduktů [M + C3H5N]+. při APCI za přítomnosti acetonitrilu. Methylestery mastných kyselin (FAMEs) byly analyzovány HPLC/APCI-MS2 se 100% acetonitrilem jako mobilní fází. Při APCI docházelo v plynné fázi k tvorbě reaktivních částic, vznikajících ze složek mobilní fáze, které se vázaly na násobné vazby v alifatickém řetězci FAMEs za vzniku aduktu [M + C3H5N]+.. Kolizně indukovanou disociací (CID) aduktu [M + C3H5N]+., se získaly diagnostické fragmenty určující polohu (polohy) násobných vazeb. Zmíněná metoda byla evaluována pro běžně analyzované polynenasycené FAMEs s tradiční polohu dvojných vazeb (methylene-interrupted).
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Structural characterization of fatty acids with triple bond and unusual double bond positions by HPLC/APCI-MS2
Horká, Petra ; Vrkoslav, Vladimír ; Cvačka, Josef
Fatty acid methyl esters (FAMEs) were analyzed by reversed-phase HPLC coupled to atmospheric pressure chemical ionization (APCI) mass spectrometry. Acetonitrile was used as mobile phase. The gas-phase reactions of acetonitrile and unsaturated FAMEs in the APCI source provided [M + C3H5N]+• adducts. Subsequent MS/MS analysis of these ions gave diagnostic fragments. The formation and fragmentation of the acetonitrile-related adducts were utilized for the structural characterization of FAME with isolated double bonds in (Z)-9,19-hexacosadienoic acid methyl ester, FAME with conjugated double bonds in (Z)-9,11-octadecadienoic acid methyl ester and FAME with a triple bond in 9-octadecynoic acid methyl ester.
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Temperature-programed micro-HPLC analysis of fatty acid methyl esters with APCI-MS detection
Vrkoslav, Vladimír ; Rumlová, Barbora ; Cvačka, Josef
HPLC/APCI-MS analysis at microliters-per-minute flow rates was optimized for separation of fatty acid methyl esters (FAMEs). HPLC C18 column with an internal diameter of 0.3 mm and isocratic elution using 99.9 % acetonitrile and 0.1% formic acid were employed. Standard APCI ion source was suitable for detection of FAMEs at 10 μl/min flow rate with the detection limit of micrograms-per-milliliter. APCI-MS spectra with predominant [M + H]+ molecular adducts were observed. The main advantage of micro-flow measurements is the possibility of using a temperature gradient, which significantly reduces retention times of FAMEs with longer aliphatic chain. The significant reduction of solvent consumption is also an important economic and environmental advantage. The positions of double bonds in FAME chains were established using acetonitrile-related adducts and tandem mass spectrometry. The optimized method was applied for analysis of FAMEs in triacylglycerol fraction of black currant seeds oil.
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Ambient ionization techniques
Vrkoslav, Vladimír
In the first part of the lecture definition and classification of ambient ionization techniques were described. In the next part the principles of the most important ambient ionization techniques were explained and their use was mentioned.
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Development of sensors based on porous silicon
Vrkoslav, Vladimír ; Jelínek, Ivan (advisor) ; Mička, Zdeněk (referee) ; Herynková, Kateřina (referee) ; Volf, Radko (referee)
5 Conclusion PS samples with defined macroporous structure were prepared and they were used as sensing layer in PL chemical sensors' concentration dependence of pL quenching response of standard PS was measured ro,ío*orogical set of linear alcohols in gas and liquid phase. From oU*'""a *tl"l"tion' of quenching sensitivity with dielecnic constant and saturated vapour it""ut" in gas and liquid phases follolrs: r. :r _L^-a io .nnrrolled bv dielectric - PL quancbing response of PS in liquid phase is controlled by streng*r ofmlYta - PL quenching response of PS in gas phase is controlled more by equilibriumconcentrationofanalýeinsideporousmatrix.Dielectric strength of analýe is not so important. PSsurfaceswerefunctionalizedwithcobaltphthalocyanine, polypyrrole, permethyl-6r-heptenoylamino-6I-deoxy B-cyclodextrins' methyl-lO-undeceonate and by oxidation' (The work is focused on using the first three compounds') We performed a measurement of concentration dependence of PL sensor response functionalized PS samples for selected organic species in gas phase' We can conclude that the PL quenching.",pň," was modiťred by functionalization of PS with selected compounds, due to change of surface polarity and molecular recognition. The magnitude of sensor response modification is dependent on kind of anallte' Another...
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