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Studies of reactions of ions with water molecules in the gaseous phase for trace gas analysis
Lacko, Michal ; Španěl, Patrik (advisor) ; Milosavljevič, Aleksandar (referee) ; Poterya, Viktoriya (referee)
Chemical ionization mass spectrometry (CI-MS) is a powerful analytical technique, capable to detect trace levels of organic molecules diluted in air samples in real-time. Processes leading to ionization of organic molecules, necessary for their detection and identification, are however often strongly affected by the presence of water vapours in form of sample humidity. In the present work, I studied the influence of water vapours on ion chemistry and, subsequently, the respective influence on sensitivity and selectivity of CI-MS techniques. Studies were carried out using several soft chemical ionization mass spectrometry instruments, including Selected Ion Flow Tube Mass Spectrometry (SIFT-MS), Proton Transfer Reaction Mass Spectrometry (PTR-MS) and Selected Ion Flow-Drift Tube Mass Spectrometry (SIFDT-MS). Experimental studies were also supplemented by theoretical simulation of proposed ion chemistry using the Kinetic of Ion-Molecular Interaction simulator (KIMI), developed by the author. In this thesis, I present a study of formaldehyde, glyoxal and phthalates ion chemistry with H3O+ , NO+ and O2 + reagent ions, focusing on secondary reactions with water vapours. Additionally, I also studied secondary reactions of protonated hydrated acetic acid with acetone. Finally, I have carried out...
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Studies of reactions of ions with water molecules in the gaseous phase for trace gas analysis
Lacko, Michal ; Španěl, Patrik (advisor)
Chemical ionization mass spectrometry (CI-MS) is a powerful analytical technique, capable to detect trace levels of organic molecules diluted in air samples in real-time. Processes leading to ionization of organic molecules, necessary for their detection and identification, are however often strongly affected by the presence of water vapours in form of sample humidity. In the present work, I studied the influence of water vapours on ion chemistry and, subsequently, the respective influence on sensitivity and selectivity of CI-MS techniques. Studies were carried out using several soft chemical ionization mass spectrometry instruments, including Selected Ion Flow Tube Mass Spectrometry (SIFT-MS), Proton Transfer Reaction Mass Spectrometry (PTR-MS) and Selected Ion Flow-Drift Tube Mass Spectrometry (SIFDT-MS). Experimental studies were also supplemented by theoretical simulation of proposed ion chemistry using the Kinetic of Ion-Molecular Interaction simulator (KIMI), developed by the author. In this thesis, I present a study of formaldehyde, glyoxal and phthalates ion chemistry with H3O+ , NO+ and O2 + reagent ions, focusing on secondary reactions with water vapours. Additionally, I also studied secondary reactions of protonated hydrated acetic acid with acetone. Finally, I have carried out...
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Elementary Processes at Low Temperatures - Reactions of H3+ and N2H+ in Afterglow Plasmas
Kálosi, Ábel ; Plašil, Radek (advisor) ; Rubovič, Peter (referee) ; Španěl, Patrik (referee)
Electron-ion recombination and ion-neutral interactions play a piv- otal role in the chemical evolution of molecules in the Interstellar Medium (ISM). Physical conditions under which these processes un- dergo in the ISM include a wide range of temperatures and particle number densities. This work contributes to the experimental study of named low temperature phenomena in the range of 30 K to 300 K focusing on the reactions of hydrogen-containing light molecules. The employed experimental techniques are based on a combination of a Stationary Afterglow (SA) instrument with a Continuous Wave Cavity Ring-down Spectrometer (cw-CRDS). The main contributions of this work can be split into three topics. (1) The proton and deuteron con- taining isotopic system of H3 + ions. The isotopic fractionation process in collisions with hydrogen and deuterium gas was investigated in low temperature discharges, nominal ion temperatures of 80 K to 140 K, to deduce relative ion densities in the experiments. These are necessary for afterglow studies of isotopic effects in electron-ion recombination of the studied ions. (2) Vibrational spectroscopy of N2H+ ions focusing on first overtone (2ν1 band) transitions and ion thermometry, the first step towards studies of electron-ion recombination. (3) The role of para/ortho spin...
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Study of state selected interactions of ions with molecular hydrogen at temperatures relevant to astrochemistry
Zymak, Illia ; Glosík, Juraj (advisor) ; Bánó, Gregor (referee) ; Španěl, Patrik (referee)
In this work are presented results of the experimental study of state selected reactions of H+ and N+(3PJa) ions with molecular hydrogen H2(J = 0, 1) at temperatures in the range 10 - 100 K using 22-pole rf ion trap apparatus. These reactions are important for the formation of interstellar trihydrogen cations and ammonia. To determine the temperature of ions, calibration measurements of the Doppler broadening of spectral lines using N2+ + Ar Ar+ + N2 laser induced reaction and rate of the ternary association He+ + 2He He2+ + He were performed. Both ternary and radiative channels of the H+ + H2(J) association reaction were observed at hydrogen number densities in the range 1012 - 1014 cm-3 and 1011 - 1012 cm-3 respectively. Obtained temperature dependences at 11 - 33 K demonstrate substantial role of the H2 rotational energy, results cannot be explained with the existed theories of the stabilization of collisional complexes. Measurements of the rate coefficient of N+(3PJa) + H2(J) reaction at different ortho fractions of H2 show dependence on internal energy of both reactants. State specific rate coefficients of the reaction of nitrogen and hydrogen ions were derived. The adiabatic model and collisional relaxations of N+(3PJa) fine structure levels were considered. Powered by TCPDF (www.tcpdf.org)
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New mass spectrometric methods for trace gas analysis of human breath.
Brůhová Michalčíková, Regina ; Španěl, Patrik (advisor) ; Polášek, Miroslav (referee) ; Tichý, Milan (referee)
This dissertation thesis summarizes results of experiments that have been carried out during my PhD studies related to the new mass spectrometric methods for trace gas analysis of human breath. The thesis is divided into the theoretical and experimental part. The chapter at the beginning of this dissertation summarizes the current research in the area of breath analysis. It is describing the common breath metabolites, benefits and challenges of the method for therapeutic monitoring and clinical diagnosis and current applications. The next chapter of the theoretical introduction describes the techniques suitable for this area of research, with a special emphasis on mass-spectrometric techniques (in particular the selected ion flow tube mass spectrometry, SIFT-MS, method that allows accurate quantification of trace gases and vapours in humid air/human breath). All these parts are elaborated via the scientific literature review. The following chapters are then directly related to my own research and describes the conducted experiment, including the results obtained. This experimental part "Results and Discussion" is divided to the individual subsections, which are conceived as the commentaries to the enclosed research papers published in peer reviewed journals. The first is the detailed step by step...
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Selected ion flow tube mass spectrometry, SIFT-MS
Sovová, Kristýna ; Španěl, Patrik (advisor) ; Glosík, Juraj (referee) ; Matejčík, Štefan (referee)
This thesis describes research that has been carried out during the years 2009-2013 as a part of my PhD project related to the method of selected ion flow tube mass spectrometry (SIFT-MS) and its application in interdisciplinary areas of research. SIFT-MS is a method that allows accurate quantification of trace gases and vapours presented in humid air with the focus on human breath; without any sample preparation and in real time. The thesis is divided into several parts. The first part reviews the history of mass spectrometry as a background for the quantitative analytical methods as PTR-MS and SIFT-MS. The second part discusses the detailed history of development of SIFT-MS, starting from principles of selected ion flow tube (SIFT) technique that has been used for study of ion-molecule reactions in the gas phase and forms the basis of SIFT-MS. The next part discusses volatile organic compounds of different biological origin: bacterial, plant and human breath metabolites that can be analyzed in real time using SIFT-MS. The main part "Results and Discussion" is divided into several subsections that serve as commentaries to the enclosed research papers published in peer reviewed journals. The first is a detailed step by step overview of the kinetics of ion molecule reactions which is the basis of...
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Water formation in reactions of anions and/or cations with molecular hydrogen at low temperature
Tran, Thuy Dung ; Plašil, Radek (advisor) ; Španěl, Patrik (referee) ; Rubovič, Peter (referee)
In the present work, the results of the experimental study of reactions of ions with molecular hydrogen in the temperature range 15 - 300 K using a 22-pole ion trap apparatus are presented. The reaction of OD- with para-enriched hydrogen was studied using a combination of the 22-pole ion trap apparatus with a para-hydrogen generator. Also reactions of O- with H2, D2, and HD were studied. These reactions have a channel of water production and a channel of hydrogen or deuterium transfer. Another field of study was a sequence of reactions of oxygen hydride cations with H2 and D2 which leads to the production of H3O+ or its isotopic variant, specifically reactions OH+ with H2, H2O+ with H2, D2O+ with H2, and D2O+ with D2. This reaction chain can be followed by the electron recombination of H3O+ or its isotopologue, which has a channel of water production.
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New mass spectrometric methods for trace gas analysis of human breath.
Brůhová Michalčíková, Regina ; Španěl, Patrik (advisor) ; Polášek, Miroslav (referee) ; Tichý, Milan (referee)
This dissertation thesis summarizes results of experiments that have been carried out during my PhD studies related to the new mass spectrometric methods for trace gas analysis of human breath. The thesis is divided into the theoretical and experimental part. The chapter at the beginning of this dissertation summarizes the current research in the area of breath analysis. It is describing the common breath metabolites, benefits and challenges of the method for therapeutic monitoring and clinical diagnosis and current applications. The next chapter of the theoretical introduction describes the techniques suitable for this area of research, with a special emphasis on mass-spectrometric techniques (in particular the selected ion flow tube mass spectrometry, SIFT-MS, method that allows accurate quantification of trace gases and vapours in humid air/human breath). All these parts are elaborated via the scientific literature review. The following chapters are then directly related to my own research and describes the conducted experiment, including the results obtained. This experimental part "Results and Discussion" is divided to the individual subsections, which are conceived as the commentaries to the enclosed research papers published in peer reviewed journals. The first is the detailed step by step...
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Elementary Processes at Low Temperatures - Reactions of H3+ and N2H+ in Afterglow Plasmas
Kálosi, Ábel ; Plašil, Radek (advisor) ; Rubovič, Peter (referee) ; Španěl, Patrik (referee)
Electron-ion recombination and ion-neutral interactions play a piv- otal role in the chemical evolution of molecules in the Interstellar Medium (ISM). Physical conditions under which these processes un- dergo in the ISM include a wide range of temperatures and particle number densities. This work contributes to the experimental study of named low temperature phenomena in the range of 30 K to 300 K focusing on the reactions of hydrogen-containing light molecules. The employed experimental techniques are based on a combination of a Stationary Afterglow (SA) instrument with a Continuous Wave Cavity Ring-down Spectrometer (cw-CRDS). The main contributions of this work can be split into three topics. (1) The proton and deuteron con- taining isotopic system of H3 + ions. The isotopic fractionation process in collisions with hydrogen and deuterium gas was investigated in low temperature discharges, nominal ion temperatures of 80 K to 140 K, to deduce relative ion densities in the experiments. These are necessary for afterglow studies of isotopic effects in electron-ion recombination of the studied ions. (2) Vibrational spectroscopy of N2H+ ions focusing on first overtone (2ν1 band) transitions and ion thermometry, the first step towards studies of electron-ion recombination. (3) The role of para/ortho spin...
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