Comments on the Observation of Ionic Equilibria in High‐Pressure Mass‐Spectrometer Ion Sources

1970 ◽  
Vol 53 (5) ◽  
pp. 2130-2131 ◽  
Author(s):  
Lewis Friedman
Keyword(s):  
High Pressure ◽  
Mass Spectrometer ◽  
Ion Sources ◽  
Ionic Equilibria

An Electron Current and Energy Regulator for Mass Spectrometer Ion Sources

1954 ◽  
Vol 25 (11) ◽  
pp. 1083-1088 ◽  
Author(s):  
Dwight A. Hutchison ◽  
Jay R. Wolff
Keyword(s):  
Mass Spectrometer ◽  
Ion Sources ◽  
Electron Current

The gas phase reactivity of the dimethylchloronium ion with alkylbenzenes

1981 ◽  
Vol 59 (15) ◽  
pp. 2412-2416 ◽  
Author(s):  
John A. Stone ◽  
Margaret S. Lin ◽  
Jeffrey Varah
Keyword(s):  
High Pressure ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Aromatic Hydrocarbons ◽  
Relative Rate ◽  
Ion Source ◽  
Nucleophilic Displacement ◽  
Rate Of Reaction ◽  
Displacement Reactions ◽  
Bonded Complexes

The reactivity of the dimethylchloronium ion with a series of aromatic hydrocarbons has been studied in a high pressure mass spectrometer ion source using the technique of reactant ion monitoring. Benzene is unreactive but all others, from toluene to mesitylene, react by CH3+ transfer to yield σ-bonded complexes. The relative rate of reaction increases with increasing exothermicity in line with current theories of nucleophilic displacement reactions.

A Deep-Ocean Mass Spectrometer to Monitor Hydrocarbon Seeps and Pipelines

2005 ◽  
Author(s):  
Gary M. McMurtry ◽  
John C. Wiltshire ◽  
Arnaud Bossuyt
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Mass Spectrometer ◽  
Deep Ocean ◽  
Rechargeable Batteries ◽  
Vacuum System ◽  
Power Cable ◽  
Electron Multiplier ◽  
Trace Contaminant

New developments in instrumentation for ocean environmental engineering are allowing unprecedented levels of trace contaminant measurement in the deep ocean. With funding from the U.S. National Science Foundation (NSF), our engineering design team constructed a new mass spectrometer-based in situ analysis system for work in the deep ocean environment over prolonged deployment periods. Our design goals were a depth capability of up to 4,000 m water depth (400 bars hydrostatic pressure) and autonomous operation for periods of up to six months to a year, depending upon the type of external battery system used or other deployment circumstances, e.g., availability of a power cable or fuel cell power source. We chose a membrane introduction mass spectrometry (MIMS) sampling approach, which allows for dissolved gases and volatile organics introduction into the mass spectrometer vacuum system. The MIMS approach and the hydrophobic, silicon-coated membrane chosen both draw upon our previous experience with this technology in the deep ocean. The membrane has been tested to 400 bars in a series of long-term hydrostatic pressure tests, which extend the 200-bar working depth rating of this membrane by a factor of 2. Long-term deployment capability of the moderately powered, approximately 100 W system, was accomplished by power management of the embedded computer system and custom electronics with Windows-based and custom software now fully-developed and bench tested. The entire system fits within a 6.5-inch outside diameter pressure housing that is approximately five feet long. It consists of a 1 to 200 amu range quadrupole mass spectrometer equipped with Faraday and electron multiplier detectors, compact turbo-molecular and backing diaphragm vacuum pumps, internal rechargeable batteries, and internal waste vacuum chamber. Sample routing past the MIMS is accomplished by computer-controlled solenoid valves. We designed the pressure housings of both 6AL4V and type 2 titanium alloys that are rated to working depths of >4,000 m and are essentially corrosion proof over long-term deployments. We designed and integrated a fail-safe valving system for both rapid response to high-pressure MIMS failure and a pressure-switch circuit and high-pressure solenoid valve to detect and protect against slow leaks of the MIMS. To route sample waters to the MIMS-based instrument, we also designed and built a rugged plastic plenum that couples to the face of the sampler head, the latter of which consists of the MIMS inlet and a full-ocean rated thermister temperature probe with an operational range from −5 to 50°C. These instrumentation innovations will be described in the paper.

High-resolution mass spectrometer for liquid metal ion sources

2013 ◽  
Vol 84 (9) ◽  
pp. 093305 ◽  
Author(s):  
Martin Wortmann ◽  
Arne Ludwig ◽  
Jan Meijer ◽  
Dirk Reuter ◽  
Andreas D. Wieck
Keyword(s):  
High Resolution ◽  
Liquid Metal ◽  
Mass Spectrometer ◽  
Metal Ion ◽  
Ion Sources ◽  
High Resolution Mass ◽  
High Resolution Mass Spectrometer ◽  
Resolution Mass

The formation of (CH3)7Si2+ in (CH3)4Si/CH4 mixtures and CH3− exchange reactions between (CH3)4Si, (CH3)4Ge, and (CH3)4Sn studied by high pressure mass spectrometry

1987 ◽  
Vol 65 (12) ◽  
pp. 2849-2854 ◽  
Author(s):  
Anastasia C. M. Wojtyniak ◽  
Xiaoping Li ◽  
John A. Stone
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Equilibrium Constant ◽  
Mass Spectrometer ◽  
Excellent Agreement ◽  
Ion Source ◽  
Methyl Groups ◽  
Exchange Reactions ◽  
Equilibrium Reactions ◽  
Association Equilibrium

The association equilibrium [Formula: see text] has been studied in a high pressure mass spectrometer ion source using tetramethylsilane/methane mixtures. Measurement of the equilibrium constant over a range of temperatures yields ΔH0 = −22.3 ± 0.4 kcal mol−1 and ΔS0 = −35.2 ± 0.9 cal mol−1 K−1. Collision-assisted dissociation experiments suggest that the methyl groups retain their integrity in (CH3)7Si2+. Mixed ions such as (CH3)7SiGe+ and (CH3)7GeSn+ were not observed in mixtures of (CH3)4X and (CH3)4Y(X ≠ Y = Si, Ge, Sn). Instead CH3− transfer equilibrium reactions were observed viz. [Formula: see text] (ΔH0 = −10.2 ± 1.2 kcal mol−1, ΔS0 = −3.7 ± 2.4 cal K−1 mol−1) and [Formula: see text], ΔS0 = −0.9 ± 1.6 cal K−1 mol−1. These are in excellent agreement with some published differences in appearance potentials for (CH3)3X+ from (CH3)4X (X = Si, Ge, Sn).

Loss of atomic oxygen in mass spectrometer ion sources

1973 ◽  
Vol 78 (10) ◽  
pp. 1645-1653 ◽  
Author(s):  
Leo R. Lake ◽  
Alfred O. Nier
Keyword(s):  
Mass Spectrometer ◽  
Atomic Oxygen ◽  
Ion Sources
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