Measurements of equilibria and reactivity of cluster ions at atmospheric pressure: reactions of Cl-(CHCl3)0-2 with methyl bromide and methyl iodide

1993 ◽  
Vol 97 (7) ◽  
pp. 1318-1323 ◽  
Author(s):  
K. Giles ◽  
E. P. Grimsrud
Keyword(s):  
Methyl Iodide ◽  
Methyl Bromide ◽  
Atmospheric Pressure ◽  
Cluster Ions

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.

Methyl bromide, other brominated methanes, and methyl iodide in polar firn air

2001 ◽  
Vol 106 (D2) ◽  
pp. 1595-1606 ◽  
Author(s):  
W. T. Sturges ◽  
H. P. McIntyre ◽  
S. A. Penkett ◽  
J. Chappellaz ◽  
J.-M. Barnola ◽  
...  
Keyword(s):  
Methyl Iodide ◽  
Methyl Bromide

METHYL BROMIDE AND ETHYLENE OXIDE FUMIGATION OFSYNCHYTRIUM ENDOBIOTICUM

1970 ◽  
Vol 50 (6) ◽  
pp. 649-658 ◽  
Author(s):  
H. A. U. MONRO ◽  
C. T. BUCKLAND ◽  
O. A. OLSEN
Keyword(s):  
Ethylene Oxide ◽  
Methyl Bromide ◽  
Atmospheric Pressure ◽  
Potato Wart ◽  
Synchytrium Endobioticum

Methyl bromide (2.5% by volume) and ethylene oxide (2.0% by volume) in vacuum fumigation for 4 hr at 25 C killed all of the resting sporangia of the potato wart fungus, Synchytrium endobioticum (Schilb.) Perc. Methyl bromide was also effective at atmospheric pressure at 4.0% for 4 hr and at 0.25% for 16 hr at 25 C. No advantage was gained by mixing the two gases in any proportions. The use of these fumigants under normal commercial conditions to prevent the spread of the organism in commodities such as jute (burlap) bags is considered feasible.

scholarly journals Strain IMB-1, a Novel Bacterium for the Removal of Methyl Bromide in Fumigated Agricultural Soils

1998 ◽  
Vol 64 (8) ◽  
pp. 2899-2905 ◽  
Author(s):  
Tracy L. Connell Hancock ◽  
Andria M. Costello ◽  
Mary E. Lidstrom ◽  
Ronald S. Oremland
Keyword(s):  
Methyl Iodide ◽  
Methyl Bromide ◽  
Agricultural Soils ◽  
Treatment Strategies ◽  
Methyl Chloride ◽  
Methylotrophic Bacterium ◽  
Rrna Gene ◽  
Low Concentrations ◽  
Novel Bacterium ◽  
Bacterium Strain

ABSTRACT A facultatively methylotrophic bacterium, strain IMB-1, that has been isolated from agricultural soil grows on methyl bromide (MeBr), methyl iodide, methyl chloride, and methylated amines, as well as on glucose, pyruvate, or acetate. Phylogenetic analysis of its 16S rRNA gene sequence indicates that strain IMB-1 classes in the alpha subgroup of the class Proteobacteria and is closely related to members of the genus Rhizobium. The ability of strain IMB-1 to oxidize MeBr to CO2 is constitutive in cells regardless of the growth substrate. Addition of cell suspensions of strain IMB-1 to soils greatly accelerates the oxidation of MeBr, as does pretreatment of soils with low concentrations of methyl iodide. These results suggest that soil treatment strategies can be devised whereby bacteria can effectively consume MeBr during field fumigations, which would diminish or eliminate the outward flux of MeBr to the atmosphere.

scholarly journals Alternatives to Methyl Bromide for Strawberry Runner Plant Production

HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1709-1715 ◽  
Author(s):  
Zahangir Kabir ◽  
Steven A. Fennimore ◽  
John M. Duniway ◽  
Frank N. Martin ◽  
Gregory T. Browne ◽  
...  
Keyword(s):  
Methyl Iodide ◽  
Methyl Bromide ◽  
High Elevation ◽  
Fruit Production ◽  
Environmental Risks ◽  
Plant Production ◽  
Soil Fumigant ◽  
Yield And Quality ◽  
Production Cycles ◽  
Strawberry Runner

For years, strawberry (Fragaria ×ananassa L.) runner plant nurseries have relied on methyl bromide (MB) fumigation of soil to produce healthy transplants. Methyl bromide, however, has been phased out due to its environmental risks. The potential for alternative fumigants to replace MB was evaluated at low and high elevation strawberry nurseries in California. The alternative fumigant iodomethane plus chloropicrin (IMPic) and a nonfumigated control (NF) were compared to methyl bromide plus chloropicrin (MBPic) at a low elevation nursery (LEN) and at a high elevation nursery (HEN) near Susanville, Calif. At a HEN near Macdoel, Calif., MBPic was compared to alternative fumigants IMPic, 1,3-dichloropropene plus chloropicrin mixture (Telone C35) followed by dazomet, chloropicrin (Pic) followed by dazomet and NF. Plants produced at the LEN were transplanted at the Macdoel HEN to measure the effects of soil fumigant history on plant health and runner plant production. Plants produced at both high elevation nurseries were evaluated for fruit yield and quality at two commercial fruit production sites in soils previously fumigated with MBPic or Pic. Runner plant production at the nurseries was similar in plots fumigated with either MBPic or alternative fumigants. All fumigation treatments had higher runner plant production than plants produced for two production cycles on NF soils. Generally, fruit yields from nursery plants produced on soils fumigated with IMPic, Pic followed by dazomet, or Telone C35 followed by dazomet, were similar to fruit yields from plants produced on MBPic fumigated soils. Overall, our results indicate that preplant soil treatments with IMPic, Pic followed by dazomet, and Telone C35 followed by dazomet, are potential alternatives to MBPic fumigation for strawberry runner plant nurseries. Fruit yields by plants in MBPic and Pic fumigated soils were comparable; however, they were more variable in Pic fumigated soils. Chemical names used: 1,3-dichloropropene (1,3-D), methyl bromide, methyl iodide (iodomethane), trichloronitromethane (chloropicrin), tetrahydro-3, 5-dimethyl-2 H-1,3,5-thiadiazine-2-thione (dazomet).

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