scholarly journals A novel rocket-borne ion mass spectrometer with large mass range: instrument description and first-flight results

2021 ◽  
Vol 14 (2) ◽  
pp. 983-993
Author(s):  
Joan Stude ◽  
Heinfried Aufmhoff ◽  
Hans Schlager ◽  
Markus Rapp ◽  
Frank Arnold ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Negative Ions ◽  
Mass Range ◽  
Large Mass ◽  
Molecular Ions ◽  
Negative Ion ◽  
Cluster Ions ◽  
The Arctic ◽  
Atmospheric Species ◽  
Smoke Particles

Abstract. We present a novel rocket-borne ion mass spectrometer named ROMARA (ROcket-borne MAss spectrometer for Research in the Atmosphere) for measuring atmospheric positive and negative ions (atomic, molecular and cluster ions) and positively and negatively charged meteor smoke particles. Our ROMARA instrument has, compared to previous rocket-borne ion mass spectrometers, a markedly larger mass range of up to m/z 2000 and a larger sensitivity, particularly for meteor smoke particle detection. The major objectives of this first ROMARA flight included the following: a functional test of the ROMARA instrument, measurements between 55 and 121 km in the mass range of atmospheric positive and negative ions, a first attempt to conduct mass spectrometric measurements in the mass range of meteor smoke particles with mass-to-charge ratios up to m/z 2000, and measurements inside a polar mesospheric winter echo layer as detected by ground-based radar. Our ROMARA measurements took place on the Arctic island of Andøya, Norway, at around noon in April 2018 and represented an integral part of the polar mesospheric winter radar echo (PMWE) rocket campaign. During the rocket flight, ROMARA was operated in a measurement mode, offering maximum sensitivity and the ability to qualitatively detect total ion signatures even beyond its mass-resolving mass range. On this first ROMARA flight we were able to meet all of our objectives. We detected atmospheric species including positive atomic, molecular and cluster ions along with negative molecular ions up to about m/z 100. Above m/z 2000, ROMARA measured strong negative-ion signatures, which are likely due to negatively charged meteor smoke particles.

scholarly journals A novel rocket borne ion mass spectrometer with large mass range: instrument description and first flight results

2020 ◽  
Author(s):  
Joan Stude ◽  
Heinfried Aufmhoff ◽  
Hans Schlager ◽  
Markus Rapp ◽  
Frank Arnold ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Negative Ions ◽  
Mass Range ◽  
Large Mass ◽  
Molecular Ions ◽  
Negative Ion ◽  
Cluster Ions ◽  
The Arctic ◽  
Atmospheric Species ◽  
Smoke Particles

Abstract. We present a novel rocket borne ion mass spectrometer ROMARA (ROcket borne MAss spectrometer for Research in the Atmosphere) for measurements of atmospheric positive and negative ions (atomic, molecular and cluster ions) and positively and negatively charged meteor smoke particles. Our ROMARA instrument has, compared to previous rocket borne ion mass spectrometers, a markedly larger mass range of up to m/z 2000 and a larger sensitivity, particularly for meteor smoke particle detection. Mayor objectives of this first ROMARA flight included: a functional test of the ROMARA instrument, measurements between 55 km and 121 km in the mass range of atmospheric positive and negative ions, a first attempt to conduct mass spectrometric measurements in the mass range of meteor smoke particles with mass to charge ratios up to m/z 2000, and measurements inside a polar mesospheric winter echo layer as detected by ground based radar. Our ROMARA measurements took place on the Arctic island of Andøya/Norway around noon in April 2018 and represented an integral part of the PMWE rocket campaign. During the rocket flight, ROMARA was operated in a measurement mode, offering maximum sensitivity and the ability to qualitatively detect total ion signatures even beyond its mass resolving mass range. On this first ROMARA flight we were able to meet all of our objectives. We detected atmospheric species including positive atomic, molecular and cluster ions along with negative molecular ions up to about m/z 100. Above m/z 2000, ROMARA measured strong negative ion signatures, which are likely due to negatively charged meteor smoke particles.

scholarly journals Characterisation of the transfer of cluster ions through an atmospheric pressure interface time-of-flight mass spectrometer with hexapole ion guides

2019 ◽  
Vol 12 (10) ◽  
pp. 5231-5246 ◽  
Author(s):  
Markus Leiminger ◽  
Stefan Feil ◽  
Paul Mutschlechner ◽  
Arttu Ylisirniö ◽  
Daniel Gunsch ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Atmospheric Pressure ◽  
Time Of Flight ◽  
Mass Range ◽  
Transmission Efficiency ◽  
Binding Energies ◽  
Cluster Ions ◽  
Ion Transfer ◽  
Flight Mass Spectrometer ◽  
Ion Guides

Abstract. Here we present an alternative approach of an atmospheric pressure interface (APi) time-of-flight mass spectrometer for the study of atmospheric ions and cluster ions, the so-called ioniAPi-TOF. The novelty is the use of two hexapoles as ion guides within the APi. In our case, hexapoles can accept and transmit a broad mass range enabling the study of small precursor ions and heavy cluster ions at the same time. Weakly bound cluster ions can easily de-cluster during ion transfer depending on the voltages applied to the ion transfer optics. With the example system of H3O+(H2O)n=0-3, we estimate that cluster ions with higher binding energies than 17 kcal mol−1 can be transferred through the APi without significant fragmentation, which is considerably lower than about 25 kcal mol−1 estimated from the literature for APi-TOFs with quadrupole ion guides. In contrast to the low-fragmenting ion transfer, the hexapoles can be set to a high-fragmenting declustering mode for collision-induced dissociation (CID) experiments as well. The ion transmission efficiency over a broad mass range was determined to be on the order of 1 %, which is comparable to existing instrumentation. From measurements under well-controlled conditions during the CLOUD experiment, we demonstrate the instrument's performance and present results from an inter-comparison with a quadrupole-based APi-TOF.

Negative Ionen durch Elektronenstoß aus organischen Nitroverbindungen, Äthylnitrit und Äthylnitrat

1967 ◽  
Vol 22 (5) ◽  
pp. 700-704
Author(s):  
K. Jäger ◽  
A. Henglein
Keyword(s):  
Electron Impact ◽  
Negative Ions ◽  
Molecular Ions ◽  
Ion Source ◽  
Negative Ion ◽  
Electron Affinities ◽  
Low Intensity ◽  
Ion Molecule Reactions ◽  
Fragment Ions ◽  
Product Ions

Negative ion formation by electron impact has been studied in nitromethane, nitroethane, nitrobenzene, tetranitromethane, ethylnitrite and ethylnitrate. Appearance potentials, ionization efficiency curves and kinetic energies of negative ions were measured by using a Fox ion source. The electron affinities of C2H5O and of C (NO2)3 are discussed as well as the energetics of processes which yield NO2-. The electron capture in nitrobenzene and tetranitromethane leads to molecular ions [C6H5NO2~ in high, C (NO2)4 in very low intensity] besides many fragment ions. A number of product ions from negative ion-molecule reactions has also been found.

Negative chlorine ion chemistry in the upper stratosphere and its application to an artificially created dense electron cloud

1995 ◽  
Vol 13 (3) ◽  
pp. 296-304 ◽  
Author(s):  
S. S. Prasad
Keyword(s):  
Major Ions ◽  
Negative Ions ◽  
Electron Cloud ◽  
Negative Ion ◽  
Cluster Ions ◽  
Aerosol Formation ◽  
Ion Chemistry ◽  
Catalytic Destruction ◽  
Three Body ◽  
Chlorine Ion

Abstract. This paper discusses new potential reactions of chlorine-bearing anions (negative ions) in the upper stratosphere. These reactions are then applied to the negative-ion chemistry following the injection of an electron cloud of very high density, of the order of 106-107 e- cm-3, in the 40-45-km region. The idea is to evaluate the recently proposed scheme to mitigate ozone depletion by converting the reactive chlorine atoms at these altitudes into Cl- ions which are unreactive towards ozone, i.e., electron scavenging of Cl. We find that the previously neglected photodetachment from Cl- is fast. For an overhead sun, this process may have a rate coefficient of 0.08 s-1 when multiple scattering is included. The rate could be even higher, depending on the ground albedo. Switching reaction between Cl-·H2O and HCl might lead to the formation of Cl-·HCl anion. Possible reactions of Cl-·H2O and Cl-·HCl with O atoms could produce ClO- and Cl-2. The production of ClO- in this manner is significant because Cl- having a high photodetachment rate constant would be regenerated in the very likely reactions of ClO- with O. When these possibilities are considered, then it is found that the chlorine anions may not be the major ions inside the electron cloud due to the rapid photodetachment from Cl-. Furthermore, in such a cloud, there may be the hazard that the Cl--Cl-·H2O-ClO--Cl- cycle amounts to catalytic destruction of two O atoms. Thus, the scheme could be risky if practised in the altitude region where atomic oxygen is an important constituent. Similar conclusions apply even if the ClO- species forms ClO-3 by three-body association with O2, instead of reacting with O. It must be emphasized that the present study is speculative at this time, because none of the relevant reactions have been investigated in the laboratory as yet. Nevertheless, it is very safe to say that the scheme of ozone preservation by electron scavenging of the upper stratospheric Cl is much less certain than implied in the studies reported by its original proponents, because those studies neglected the photodetachment from Cl- and made the highly unlikely assumption that the Cl-·H2O anion neither photodissociates nor reacts any further. The situation at the lower altitudes could be even more complex due to the formation of large cluster ions and the ion-induced aerosol formation. The lower atmospheric situation, therefore, requires much more study. The uncertainties in the scavenging scheme due to the electrostatic repulsion in the cloud should also be addressed. Despite the uncertainties about its environmental engineering usefulness, the emerging technology for artificial creation of plasmas, with any desired density and charge in the stratosphere, could have significant pure scientific values in the studies of stratospheric ion chemistry and ion-induced aerosol formation. Such studies have perennially suffered from the extremely low densities of the naturally occurring plasma.

scholarly journals Characterisation of the transfer of cluster ions through an Atmospheric Pressure interface Time-of-Flight mass spectrometer with hexapole ion guides

2019 ◽  
Author(s):  
Markus Leiminger ◽  
Stefan Feil ◽  
Paul Mutschlechner ◽  
Arttu Ylisirniö ◽  
Daniel Gunsch ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Atmospheric Pressure ◽  
Time Of Flight ◽  
Mass Range ◽  
Transmission Efficiency ◽  
Binding Energies ◽  
Cluster Ions ◽  
Ion Transfer ◽  
Flight Mass Spectrometer ◽  
Ion Guides

Abstract. Here we present an alternative approach of an Atmospheric-Pressure interface (APi) Time-Of-Flight mass spectrometer for the study of atmospheric ions and cluster ions, the so-called ioniAPi-TOF. The novelty is the use of two hexapoles as ion guides within the APi. As we will show, hexapoles can accept and transmit a broad mass range enabling the study of small precursor ions and heavy cluster ions at the same time. Weakly bound cluster ions can easily de-cluster during ion transfer depending on the voltages applied to the ion transfer optics. With the example system of H3O+(H2O)n=0–3, we estimate that cluster ions with higher binding energies than 17 kcal/mol can be transferred through the APi without significant fragmentation, which is considerably lower than about 25 kcal/mol estimated from the literature for APi-TOFs with quadrupole ion guides. In contrast to the low fragmenting ion transfer, the hexapoles can be set to a high fragmenting declustering mode for collision-induced dissociation (CID) experiments as well. The ion transmission efficiency over a broad mass range was determined to be in the order of 1 %, which is comparable to existing instrumentation. From measurements under well-controlled conditions during the CLOUD experiment, we demonstrate the instrument's performance and present results from an inter-comparison with a quadrupole based APi-TOF.

Concluding remarks

1979 ◽  
Vol 293 (1400) ◽  
pp. 167-168
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Mass Spectrometer ◽  
Organic Molecules ◽  
Negative Ions ◽  
Negative Ion ◽  
Current Status ◽  
Source Analysis ◽  
Biological Chemistry ◽  
Mass Spectrometers

It is good that from time to time, a group of leading workers in a field should come together to discuss the current status of their research, and the direction in which it will most probably develop. We should all be grateful to the Royal Society in acting as hosts to this conference and to Professor Johnson and Professor Beynon for organizing it. I think that all will agree that the high quality of the papers presented have made this occasion a very memorable and valuable one. I should also like to thank the organizers for the relaxed atmosphere of the Conference, which made it so enjoyable. The last decade has seen a tremendous growth in both the instrumentation and techniques of mass spectrometry and the applications of mass spectrometry to organic and biological chemistry. On the instrumentation side, the modification of a double focusing mass spectrometer to yield ion kinetic energy spectra, giving information about the progenitors of a given ion, and the reversed geometry instrument, yielding information as to the daughter ions of a given parent, have both considerably contributed to our knowledge of the fragmentation of organic molecules. Again the development of special sources, field ionization and field desorption, the linking of a gas or high pressure liquid chromatograph to a mass spectrometer, and the introduction of high pressure sources for chemical ionization, have all made important contributions to organic and biological chemistry. The study of negative ions has also shed considerable light on the structure of organic molecules. Finally, the linking of computers with mass spectrometers has enabled results to be obtained very much more rapidly than in the past, and also made possible library searches to identify the substances present. Mr Craig discussed recent modifications in the source, analysis systems and detector systems of commercial mass spectrometers. Of particular importance was the increased sensitivity obtained by more effective ion collection. Among the newer techniques described during the meeting were g.c.-m.s. (Professor Jellum, Professor Jackson, Dr Morris, Professor Brooks and Professor Eglinton), collisional activation (Professor McLafferty and Dr Morris), negative ion mass spectrometry (Professor Jennings) and reversed geometry mass spectrometry (Professor Beynon).

scholarly journals Photoelectron Spectroscopy of Mass-Selected Copper-Water Cluster Negative Ions

1995 ◽  
Vol 15 (2-4) ◽  
pp. 195-207 ◽  
Author(s):  
Fuminori Misaizu ◽  
Keizo Tsukamato ◽  
Masaomi Sanekata ◽  
Kiyokazu Fuke
Keyword(s):  
Photoelectron Spectroscopy ◽  
Negative Ions ◽  
Photoelectron Spectra ◽  
Negative Ion ◽  
Cluster Ions ◽  
Electron Detachment ◽  
Energy Bands ◽  
Size Dependent ◽  
Spectral Shifts ◽  
Metal Atoms

Negative-ion photoelectron spectroscopy has been applied in order to obtain size dependent information about the electronic structure of clusters of metal atoms solvated with polar molecules. In the present paper we have investigated the photoelectron spectra of Cu2-(H2O)n, cluster ions with 2 = 0–4 and also those of Cu2-(H2O)n, with n = 0 and 1. In the spectra of Cu2-(H2O)n, the lowest energy bands were assigned to the electron detachment from the CuOH-(H2O)n−1, which were produced in the source together with the above cluster ions. The observed bands for Cu2-(H2O)n were all assigned to the transitions to the states originating in the ground 2S and first excited 2D states of the Cu atom. The stepwise hydration for Cu- and Cu2- was discussed from the observed spectral shifts.

Nachweis von organischen Molekülkomplexen über deren negative Ionen

1970 ◽  
Vol 25 (6) ◽  
pp. 849-852
Author(s):  
Hans Knof ◽  
Dieter Kraft
Keyword(s):  
Formic Acid ◽  
Organic Compounds ◽  
Mass Spectrometer ◽  
Pressure Dependence ◽  
Electron Attachment ◽  
Negative Ions ◽  
Molecular Ions ◽  
Ion Molecule Reactions ◽  
Ion Production ◽  
Measured Pressure

Abstract Molecular polymeres of organic compounds could be identified with a special mass spectrometer by their negative ions without fragmentation from acetone, methanol, and formic acid. Verification of these measurements was obtained by the investigation of deuterated samples. Molecular ions were measured up to trimers. Benzene and cyclohexane did not show polymer ions. The measured pressure dependence indicates preference of electron attachment in ion production against ion molecule reactions. The complexes are held together by the intermolecular dipole forces.

THE IONIZATION AND DISSOCIATION OF SOME HALOGEN MOLECULES BY ELECTRON IMPACT

1960 ◽  
Vol 38 (3) ◽  
pp. 407-420 ◽  
Author(s):  
D. C. Frost ◽  
C. A. McDowell
Keyword(s):  
Electron Impact ◽  
Excited States ◽  
Electronic Structures ◽  
Negative Ions ◽  
Molecular Ions ◽  
Negative Ion ◽  
Iodine Monochloride ◽  
Monoenergetic Electron ◽  
Iodine Monobromide ◽  
Ionization Processes

The ionization and dissociation of chlorine, bromine, iodine, iodine monochloride, and iodine monobromide by electron impact have been studied in a mass spectrometer which uses a monoenergetic electron source. Many ionization potentials have been observed for these molecules which, of course, refer to the formation of the parent molecular ions in different excited states. These experimental results are discussed in terms of simple molecular orbital theories of the electronic structures of the different halogen molecules.Electron-induced dissociative ionization processes for the different substances have also been studied. Where possible, appearance potentials of both the positive and negative ions have been determined. These results have been used to construct potential energy diagrams illustrating the origin of some of the negative ion and dissociation processes observed.

scholarly journals Determination of Electron Affinity on the Base of Experimentally Measured Lifetime of Negative Molecular Ions of Coumarin Derivatives

2020 ◽  
pp. 45-59
Author(s):  
Mansaf Tayupov ◽  
Rustam Rakhmeev ◽  
Nail Asfandiarov ◽  
Stanislav Pshenichnyuk
Keyword(s):  
Electron Affinity ◽  
Density Functional ◽  
Negative Ions ◽  
Density Functional Theory Calculations ◽  
Molecular Ions ◽  
Negative Ion ◽  
Decay Channels ◽  
Negative Ion Mass Spectrometry ◽  
Mean Lifetime ◽  
Total Energies

Resonance attachment of low-energy (0–15 eV) electrons to molecules of 4.7- and 6.7-dihydroxycoumarin was investigated by means of negative ion mass spectrometry. These natural compounds possess biological activity associated with antioxidant and bactericidal properties. The most probable structures of the fragment negative ions ([M – H]–, [M – 2H]–, [M – СО]–, [M – СОH]–, [M – СООH]– etc.) were predicted by means of analysis of decay channels for the molecular negative ions using the results of density functional theory calculations. Mean lifetime for molecular negative ions of 4.7-dihydroxycoumarin relative to electron autodetachment was measured. The adiabatic electron affinity (EAa) was estimated in the framework of the Arrhenius approximation. It was found that EAa values calculated at B3LYP/6-31+G(d) level with minimal addition of diffuse functions as a difference between the total energies of a neutral molecule and its radical anion correlate with experimental EAa values.

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