Štefan Matejčík

Štefan Matejčík
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Štefan verified their affiliation via an institutional email.
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Štefan verified their affiliation via an institutional email.
Comenius University Bratislava · Department of Experimental Physics

Professor

About

305
Publications
67,223
Reads
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4,818
Citations
Introduction
Electron and Ion physics, Mass spectrometry, Ion Mobility Spectrometry, UV-VIS spectrometry, Plasma Physics
Additional affiliations
January 1998 - present
Comenius University Bratislava
Position
  • Principal Investigator
January 1998 - December 2020
Comenius University Bratislava
Position
  • Professor (Full)
Education
September 1993 - November 1995
University of Innsbruck
Field of study
  • Physics
September 1991 - June 1998
Comenius University Bratislava
Field of study
  • Physics
September 1986 - June 1991
Comenius University Bratislava
Field of study
  • Physics

Publications

Publications (305)
Article
Full-text available
We report the results of an experimental study focused on the low-energy (10–100 eV) electron impact excitation of acetone. In the emission spectrum, the most prominent excited species were found to be the hydrogen Balmer series, the excited CH radical in the A and B electronic states, and atomic carbon. The presence of OH emission in the spectra c...
Article
This study presents a novel rapid analytical method for the detection of volatile organic compounds (VOCs) emitted from blueberry leaves using the Tenax adsorbent followed by separation using a multicapillary column (MCC) and Ion Mobility Spectrometry (IMS) detection. The emitted VOCs including caryophyllene, benzene acetonitrile, linalool, ocimene...
Article
Full-text available
A highly efficient and sensitive ion mobility spectrometry (IMS) system with laser desorption sampling was applied for rapid explosive detection using different surface materials. This portable IMS detector, powered by a battery, offers mobility and is suitable for use in the field or combat zones. The laser desorption (LD) sampling of common explo...
Article
Rationale Silane derivatives play a crucial role in industrial plasma processes for the fabrication of various electronic devices such as lighting devices, solar cells, and displays. Accurate quantitative data are essential for modeling technological plasmas. This study reports the rate coefficients (k) and activation energies (E a ) for thermal el...
Article
Rationale Compounds like caffeine metabolites with more than one proton acceptor site can produce a mixture of isomeric protonated ions (protomers) in electrospray ionization and atmospheric pressure chemical ionization (APCI) ion sources. Discrimination between the protomers is of interest as the charge location influences ion structure and chemic...
Article
Full-text available
The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak dev...
Article
Electron Attachment and corresponding Dissociative Electron Attachment (DEA) to cobalt tricarbonyl nitrosyl (Co(CO)3NO) clusters have been studied by co-expansion with Ar gas into a high vacuum. A monochromatic electron beam...
Article
Formic acid (FA) is introduced as a potent dopant for atmospheric pressure chemical ionization (APCI) for ion mobility spectrometry (IMS) and mass spectrometry (MS). The mechanism of chemical ionization with the FA dopant was studied in the negative polarity using a corona discharge (CD)-IMS-MS technique in air. Standard reactant ions of the negati...
Article
The electron attachment and dissociative electron attachment to gas phase octafluorocyclobutane (c-C4F8) and to its clusters have been measured. The majority of the gas phase products were already reported earlier and have been successfully confirmed in this work. In addition, two new fragments c-C4F7− and C2F5− have been detected at electron energ...
Raw Data
invites applications for PhD. to work on several ongoing projects related to the Ion Mobility Spectrometry, RF-discharges, Bio plasma, Electron-Induced Fluorescence, and Modeling of Electron-induced processes. An overview of our current activities is available at the following websites: http://dep.fmph.uniba.sk/ We seek motivated and highly talente...
Article
Full-text available
The processes of electron impact induced fluorescence of nitrogen were studied in the electron energy range from 6 to 100 eV and in the spectral range from 330 to 1030 nm. Using the new CCD camera Spectral Electron Energy Map of N2 was obtained. This type of data in such a wide spectral and energy range are published for the first time. The most in...
Article
In this study, negative polarity atmospheric pressure chemical ionisation-ion mobility spectrometry (APCI-IMS) was applied to study ionisation of NO2 by O2−·CO2·(H2O)n reactant ions (RI) generated in the corona discharge ionisation source. The electron transfer reaction between RI and NO2 resulted in the formation of NO2−.(H2O)n ions (drift gas tem...
Article
Methyl salicylate (MeSA) is a plant-signaling molecule that plays an essential role in the regulation of plant responses to biotic and abiotic pathogens. In this work, solid phase microextraction (SPME) and a multicapillary column (MCC) are coupled to ion mobility spectrometry (IMS) to detect MeSA in tomato leaves. The SPME-MCC-IMS method provides...
Preprint
Full-text available
The excitation of nitromethane CH$_3$NO$_2$, which is an important propellant and prototypic molecule for large class of explosives, has been investigated by electron impact and subsequent emission of photons in the UV-VIS spectral region between 300 nm and 670 nm. Emission spectrum of nitromethane was recorded at an electron energy of 50 eV. New d...
Preprint
Full-text available
The optical emission spectrum of acetylene excited by monoenergetic electrons was studied in the range of 190 nm to 660 nm. The dissociative excitation and dissociative ionization associated with excitation of the ions initiated by electron impact were dominant processes contributing to the spectrum. The spectrum was dominated by the atomic lines H...
Article
Full-text available
A low-pressure capacitively coupled radiofrequency (RF) helium discharge with a structured electrode is investigated experimentally and via kinetic simulations. In the experiment, Phase Resolved Optical Emission Spectroscopy (PROES) provides information about the excitation dynamics by high energy electrons, with high spatial and nanosecond tempora...
Article
Negative polarity atmospheric pressure chemical ionization of selected chlorinated hydrocarbons (tetrachloromethane CCl4 and hexachloroethane C2Cl6, dichloromethane CH2Cl2, trichloromethane CHCl3, 1,1,1,2-tetrachloroethane 1,1,1,2-C2H2Cl4, 1,1,2,2-tetrachloroethane 1,1,2,2,-C2H2Cl4 1,1,2-trichloroethane 1,1,2-C2H3Cl3, and 1,1,2-trichloroethane 1,1,...
Conference Paper
of Atmospheric Pressure Field Emission (APFE) ionisation source for drift tube Ion Mobility Spectrometry has been performed for negative polarity operation. Formation of the negative ions in synthetic air was studied and compared with the Atmospheric Pressure Corona Discharge (APCD) ion source. In the negative polarity the APFE ionisation source wa...
Article
Ion mobility spectrometry (IMS) equipped with a corona discharge (CD) ion source was used for measurement of three auxin plant hormones including indole-3-acetic acid (IAA), indole-3-propionic acid (IPA), and indole-3-butyric acid (IBA). The measurements were performed in both positive and negative polarities of the CD ion source. Dopant gases NH3,...
Chapter
Technika IMS-MS będąca połączeniem spektrometrii ruchliwości jonów (IMS) i spektrometrii mas (MS) wykorzystywana jest do zadań analitycznych, w których wymagane jest rozdzielanie składników próbki o zbliżonych masach. W ostatnich latach zainteresowanie tą techniką wzrosło, a głównymi obszarami zastosowań są badania medyczne, proteomika i metabolomi...
Article
In nuclear fusion reactors, plasmas are heated to very high temperatures of more than 100 million kelvin and, in so-called tokamaks, they are confined by magnetic fields in the shape of a torus. Light nuclei, such as deuterium and tritium, undergo a fusion reaction that releases energy, making fusion a promising option for a sustainable and clean e...
Article
Full-text available
Alpha particles with energies on the order of megaelectronvolts will be the main source of plasma heating in future magnetic confinement fusion reactors. Instead of heating fuel ions, most of the energy of alpha particles is transferred to electrons in the plasma. Furthermore, alpha particles can also excite Alfvénic instabilities, which were previ...
Article
An atmospheric Pressure Field Effect (APFE) ionisation source for drift tube ion mobility spectrometry has been developed for operation in positive and negative polarities. The formation of negative and positive ions in synthetic air was studied and compared with the Atmospheric Pressure Corona Discharge (APCD) ionisation source. The APFE ionisatio...
Article
Full-text available
The excitation of nitromethane (CH3NO2), which is an important propellant and prototypic molecule for large class of explosives, has been investigated by electron impact and subsequent emission of photons in the UV‐VIS spectral region between 300 nm and 670 nm. Emission spectrum of nitromethane was recorded at an electron energy of 50 eV. New disso...
Article
Full-text available
An online coupling of microchip isotachophoresis (µITP) with ion mobility spectrometry (IMS) using thermal evaporation interface is reported for the first time. This combination integrates preconcentration power of the µITP followed by unambiguous identification of trace compounds in complex samples by IMS. Short-chain carboxylic acids, chosen as m...
Article
Full-text available
In this study, we have demonstrated a separation of positional isomers of some derivatives of alkoxyphenylcarbamic acid. These compounds belong to drugs with local anesthetics activity. The low volatility compounds were analysed by a Thin Layer Chromatography (TLC) and Ion Mobility Spectrometry (IMS) using diode laser desorption for sample introduc...
Article
The latest achievements are presented in experimental and theoretical studies of resonance scattering of low-energy (0–15-eV) electrons from molecular targets in a gas phase resulting in the formation and decay of negative ions. The focus is on dissociative electron attachment spectroscopy for studying the microsecond dynamics of molecules containi...
Article
Full-text available
In this paper, the rate coefficients (k) and activation energies (Ea) for SiCl4, SiHCl3, and Si(CH3)2(CH2Cl)Cl molecules in the gas phase were measured using the pulsed Townsend technique. The experiment was performed in the temperature range of 298–378 K, and carbon dioxide was used as a buffer gas. The obtained k depended on temperature in accord...
Poster
The performance of ion mobility spectrometry (IMS) instruments is influenced by the intensity and stability of the ion source and the homogeneity of the gas flow and drift field of the IMS drift tube. These parameters have been studied and optimized using experiments and computer simulations. In the case of corona discharge ion source, we have test...
Article
Rationale: Phthalates are widely used in consumer products in the chemical industries. Due to their abundance in the milieu, their potentially harmful effect on the environment, human and animal health there is a need for sensitive and fast methods for their detection. Methods: Positive polarity Corona Discharge Atmospheric Pressure Chemical Ion...
Article
Full-text available
Ion mobility spectrometry was used to monitor the degradation of phthalate vapors by corona discharge. Three different phthalates (dimethyl [DMP], diethyl [DEP], and dipropyl [DPP]) were examined in a corona discharge reactor (wire‐to‐cylinder geometry) at direct current positive polarity in ambient air. The relative removal efficiencies up to 96%...
Article
This paper reports on the variation of the physical properties of vacuum breakdown in microgaps from the static to the pulsed electric fields in a quasi-homogeneous electric field. The measurements were performed between the spherical cathode and planar anode, both made of stainless-steel separated from 1 μm up to 10 μm at the pressure of ∼1×10−4 P...
Conference Paper
The stability of the operation of the negative corona discharge ion source for the Ion Mobility Spectrometry (IMS) has been studied. The temporal stability of the ion current was investigated as a function of wire diameter (20, 50, and 100µm) and wire material (the high-voltage electrode). The ion current generation efficiency was increasing for th...
Article
Full-text available
In this paper, we describe an efficient, massively parallel GPU implementation strategy for speeding up one-dimensional electrostatic plasma simulations based on the Particle-in-Cell method with Monte-Carlo collisions. Relying on the Roofline performance model, we identify performance-critical points of the program and provide optimised solutions....
Article
Full-text available
The electron impact excitation of N 2 O was studied using the crossed electron-molecular beams method. Optical emission spectrum initiated by 50 eV electron impact was recorded within the range 200-700 nm. Main emission bands arise from excited ion state N 2 O + (A 2 Σ) and dissociative excitation into N 2 + (B 2 Σ + u). The rotationally un-resolve...
Article
A rapid and simple method is proposed for detection of elemental mercury (Hg) vapor by ion mobility spectrometry (IMS). Negative corona discharge (CD) as the ionization source and chloroform as the dopant gas were used to produce Cl⁻ reactant ion. A mass spectrum of the product ions confirmed that the mechanism of ionization is based on Cl⁻ anion a...
Article
Full-text available
Phthalates are widely industrially used and their toxicity is of serious environmental and public health concern. Chemical ionization (CI) analytical techniques offer the potential to detect and monitor traces of phthalate vapours in air or sample headspace in real time. Promising techniques include selected ion flow tube mass spectrometry (SIFT-MS...
Article
We present an experimental and theoretical study of electron ionization (EI) of Cyclopropylamine (CPA) molecule, using crossed electron – molecular beam technique with mass spectrometric detection of the ions. We have obtained energy resolved mass spectra, and electron energy dependent ion efficiency curves for ions of particular mass charge ratios...
Article
We present the design, construction, and first spectra of a step-scan Michelson Fourier-transform spectrometer for optical emission spectroscopy in the UV–VIS spectral range. The mirror motion mechanism is based on a long-travel piezo-based linear translation stage with built-in position feedback. The step-scan arrangement allows for signal integra...
Article
In this work, we present the application of a fast and sensitive microanalytical method, microchip capillary electrophoresis (MCE), for the determination of NO2− and NO3− ions in deionized water treated by atmospheric pressure plasma jet (APPJ). The MCE technique consisted of an online combination of isotachophoresis with zone electrophoresis, both...
Article
The present study compares the operation of two cold atmospheric plasma jet (CAPJ) configurations: needle‐to‐cylinder electrode configuration (CAPJ I) and single high‐voltage cylinder electrode around the quartz tube (CAPJ II). The CAPJs were operated in argon flowing through a quartz capillary with 0.5‐mm inner diameter into the ambient air, and t...
Article
Full-text available
A global heat flux model based on a fractional derivative of plasma pressure is proposed for the heat transport in fusion plasmas. The degree of the fractional derivative of the heat flux, α, is defined through the power balance analysis of the steady state. The model was used to obtain the experimental values of α for a large database of the Joint...
Article
In this work, we present an Atmospheric Pressure Chemical Ionisation (APCI) study of several organic solvents relevant to Thin Layer Chromatography (TLC) (methanol, ethanol, propan-2-ol, acetone, ethyl acetate, diethylamine). The solvents were investigated using an Ion Mobility Spectrometry (IMS) combined with orthogonal acceleration Time Of Flight...
Article
We studied the dissociation reactions of electron impact on water vapor for several fragment species at optical and near-ultraviolet wavelengths (200–850 nm). The resulting spectrum is dominated by the hydrogen Balmer series, by the OH (A ² Σ ⁺ − X ² Π) band, and by the emission of ionic H 2 O ⁺ (A ² A 1 − X ² B 1 ) and OH ⁺ (A ³ Π − X ³ Σ ⁻ ) band...
Article
An Ion Mobility Spectrometry (IMS) apparatus has been used to detect the β-methyl-γ-octalactone (Whisky Lactone - WL) standard in the air and as well WL vapours originating from the oak wood samples. The IMS was equipped with Atmospheric Pressure Chemical Ionisation (APCI) ion source based on a Corona Discharge (CD) and was operated in the positive...
Preprint
Full-text available
We studied dissociation reactions of electron impact on water vapor for several fragment species at optical and near ultraviolet wavelengths (200 - 850 nm). The resulting spectrum is dominated by the Hydrogen Balmer series, by the OH (A $^2\Sigma^+$ - X $^2\Pi$) band, and by the emission of ionic H$_2$O$^+$ (A $^2$A$_1$ - X $^2$B$_1$) and OH$^+$ (A...
Article
This is the first report of coupling of microchip electrophoresis (MCE) with ion mobility spectrometry (IMS) for the analysis of liquid samples. Zone electrophoresis, employed on a microchip as a MCE technique, is suitable for coupling with IMS. Sample components separated electrophoretically in liquid phase were transferred from the microchip usin...
Article
In this work we have studied ionisation mechanism of Atmospheric Pressure Chemical Ionisation (ACPI) for three isomers of dimethyl phthalate (dimethyl phthalate – DMP (ortho - isomer), dimethyl isophthalate – DMIP (meta) and dimethyl terephthalate – DMTP (para)) using Ion Mobility Spectrometry (IMS) and IMS combined with orthogonal acceleration Tim...
Article
Protonation, hydration, and cluster formation of ammonia, formaldehyde, formic acid, acetone, butanone, 2-ocatanone, 2-nonanone, acetophenone, ethanol, pyridine, and its derivatives were studied by IMS-TOFMS technique equipped with a corona discharge ion source. It was found that tendency of the protonated molecules, MH⁺, to participate in hydratio...
Article
Full-text available
In this work, we present the results of an experimental study focused on characterisation of an electron gun designed for atmospheric pressure ionisation - Atmospheric Pressure Electron Gun (APEG). The APEG generates electrons with energies of several keV and could be used as replacement for β-radiation-based ionization sources for Atmospheric Pres...
Article
Ionization of 2-nonanone, cyclopentanone, acetophenone, pyridine, and di-tert-butylpyridine (DTBP) in a corona discharge (CD) atmospheric pressure chemical ionization (APCI) ion source was studied using ion mobility (IMS) and time-of-flight mass spectrometry (TOF-MS). The IMS and MS spectra were recorded in the absence and presence of ammonia dopan...
Article
Experimental investigation of electron ionization (EI) of and electron attachment (EA) onto dicyclohexyl phthalate (DCHP) was carried out using a crossed electron and molecular beam technique. Formation of positive and negative ions by EI and EA with the corresponding dissociation processes was studied and discussed. Due to a low ion yield of the p...
Article
A negative corona discharge operating at atmospheric pressure has been used to initiate chemical reactions in a gaseous mixture of nitrogen, methane, and carbon dioxide. Such a mixture simulates the composition of the early Earth's atmosphere. This work extends our previous experimental studies of the chemistry of prebiotic atmospheres generated in...
Article
In a combined experimental and theoretical study we characterize dissociative electron attachment (DEA) to, and electronically excited states of, Fe(CO)$_5$. Both are relevant for electron-induced degradation of Fe(CO)$_5$. The strongest DEA channel is cleavage of one metal-ligand bond that leads to production of Fe(CO)$_4^-$. High-resolution spect...
Article
Full-text available
In the present study we have performed electron collision experiments with copper carboxylate complexes: [Cu2(t-BuNH2)2(µ-O2CC2F5)4], [Cu2(s-BuNH2)2(µ-O2CC2F5)4], [Cu2(EtNH2)2(µ-O2CC2F5)4], and [Cu2(µ-O2CC2F5)4]. Mass spectrometry was used to identify the fragmentation pattern of the coordination compounds produced in crossed electron – molecular b...
Article
Full-text available
This paper reports on experimental studies of the breakdown mechanism in oxygen microdischarges generated in static and time-varying electric fields, up to radio-frequencies. Measurements were performed by using electrodes with round edges separated by a distance ranging between 2.5 μm and 100 μm, with the gas pressure from 7.5Torr to 700Torr. It i...
Article
2,4,6-trichloroanisole and 2,4,6-tribromoanisole were investigated by means of electron transmission spectroscopy and two different types of dissociative electron attachment spectrometers. The results obtained were interpreted with the support of density functional theory calculations. The dominant dissociative decay channels of the temporary molec...
Article
Full-text available
In this work, we probe anion production upon electron interaction with Fe(CO)5 clusters using two complementary cluster-beam setups. We have identified two mechanisms that lead to synthesis of complex anions with mixed Fe/CO composition. These two mechanisms are operative in distinct electron energy ranges. It is shown that the elementary decomposi...
Article
Full-text available
The 2014–2016 JET results are reviewed in the light of their significance for optimising the ITER research plan for the active and non-active operation. More than 60 h of plasma operation with ITER first wall materials successfully took place since its installation in 2011. New multi-machine scaling of the type I-ELM divertor energy flux density to...
Article
Full-text available
The electron impact excitation-emission cross section of argon 4P²[1/2] → 4S²[1/2]° [1] was experimentally investigated in the electron energy range 5eV − 100eV. The absolute value of the cross section was calibrated by comparison with the known cross section for the helium transition He 3¹S → 2¹P⁰ [2].
Article
Full-text available
We report our recent experimental study regarding H2 and D2 continuum radiation (a³Σg⁺ → b³Σu⁺) in the spectral range of 200 – 650 nm, excited by electron impact at near-threshold impact energies. In contrast to earlier studies, present results indicate that H2 and D2 continuum radiation is detectable in the spectral range above 500 nm. To suppleme...
Article
Full-text available
The optical emission spectrum of acetylene excited by monoenergetic electrons was studied in the range of 190–660 nm. The dissociative excitation and dissociative ionization associated with excitation of the ions initiated by electron impact were dominant processes contributing to the spectrum. The spectrum was dominated by the atomic lines (hydrog...
Article
In this paper, the results of measurements of the characteristics of the hydrogen microdischarges from direct current to radio frequencies are presented and discussed. Two types of the electrode configurations are used: electrodes with Bruce profile and glass melting electrodes separated between 2.5 and 100 μm. The breakdown voltage values for low...
Article
Full-text available
This paper presents the results of the experimental and simulation studies of the breakdown characteristics of microdischarges in compressed ambient air under the influence of static and time-varying electric fields, up to radio-frequencies. The measurements were performed for sphere to plane geometry of the electrodes separated from 5 μm to 100 μm...
Article
The exploration of planetary atmosphere is being advanced by the exciting results of the Cassin-Huygens mission to Titan. The complex chemistry revealed in such atmospheres leading to the synthesis of bigger molecules is providing new insights into our understanding of how life on Earth developed. This work extends our previous investigation of nit...
Data
We present a novel method for solids and surfaces analysis by Ion mobility spectrometry. The Advance ion mobility spectrometer (AIMS) operated in subatmospheric pressure was used in this work. The capillary inlet was used for sample aspiration to reaction region of AIMS. The sample was desorbed from surface by laser diode module. This technique was...
Conference Paper
Full-text available
Purpose: We present a novel method for coupling thin layer chromatography (TLC) with ion mobility spectrometry (IMS) using laser desorption technique (LD). After separation of the compounds by TLC, the TLC surface was sampled by the LD-IMS without any further manipulation or preparation. Experimental description: The Advance ion mobility spectromet...
Presentation
Full-text available
We present a novel method for surface analysis by Ion mobility spectrometry. The Advance ion mobility spectrometer (AIMS) operated in subatmospheric pressure was used in this work. The capillary inlet was used for sample aspiration to reaction region of AIMS. The sample was desorbed from surface by laser diode module. This technique was successfull...
Article
Full-text available
We report results of an experimental study focused on the fluorescence of H2 initiated by the impact of quasi-monochromatic electrons. The emission spectra of H2 molecules at electron energies of 25 eV, 50 eV and 100 eV have been measured in the spectral range of 320–670 nm. The emission spectrum is dominated by Balmer emission lines, Fulcher α, β,...