Kinetic study by EPR and mass spectrometry of the elementary reactions of boron tribromide with H, O, and OH radicals

1981 ◽  
Vol 85 (6) ◽  
pp. 655-658 ◽  
Author(s):  
J. L. Jourdain ◽  
G. Le Bras ◽  
J. Combourieu
Keyword(s):  
Mass Spectrometry ◽  
Kinetic Study ◽  
Oh Radicals ◽  
Elementary Reactions ◽  
Boron Tribromide

Study of the tropospheric degradation of 2-methylbutanal initiated by OH radicals, Cl atoms and sunlight

2021 ◽  
Author(s):  
María Asensio ◽  
Sergio Blázquez ◽  
María Antiñolo ◽  
José Albadalejo ◽  
Elena Jiménez
Keyword(s):  
Mass Spectrometry ◽  
Kinetic Study ◽  
Gas Phase ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
Gas Phase Kinetics ◽  
Ftir Spectrometer ◽  
Kinetics Of ◽  
Cl Atoms

<p>The biogenic oxygenated volatile compound 2-methylbutanal (2MB) is emitted into the low atmosphere from several natural sources such as microbiological processes, wildland fires, or emissions from vegetation<sup>1</sup>. Moreover, some industrial operations also generate 2MB<sup>2</sup>. During the day, the oxidation of 2MB can be initiated by sunlight, hydroxyl (OH) radicals or chlorine (Cl) atoms in marine atmospheres. Up to date, gas-phase kinetics of OH with 2MB has only been studied at room temperature<sup>3</sup>. The photolysis rate coefficients (<em>J</em>) of 2MB initiated by sunlight have also been reported<sup>4</sup>. However, there is no available data for the reaction of Cl atoms with 2MB and the photolysis products.</p><p>In this work, the photolysis rate coefficient (<em>J</em>) of 2MB has been measured using a solar simulator in a Pyrex cell coupled to a Fourier Transform Infrared (FTIR) spectrometer to monitor the loss of 2MB. Moreover, the gas-phase kinetics of the reaction of 2MB with Cl (<em>k</em><sub>Cl</sub>) and OH (<em>k</em><sub>OH</sub>) have been investigated to evaluate the contribution of these homogeneous degradation routes to the total loss of 2MB in the atmosphere. All the kinetic experiments were carried out under free-NO<sub>x</sub> conditions (simulating a clean atmosphere). Regarding the relative kinetic study on the Cl-reaction, an atmospheric simulation chamber coupled to a FTIR spectrometer was used at 298 K and 760 Torr <sup>5</sup> of air, whereas for the absolute kinetics of the OH-reaction, <em>k</em><sub>OH</sub> was determined as a function of temperature and pressure (T = 263-353 K and P = 50-600 Torr of helium) by using a pulsed laser photolysis-laser induced fluorescence system<sup>6</sup>. Finally, in addition to FTIR, gas chromatography coupled to mass spectrometry and proton transfer time-of-flight mass spectrometry were used to detect the gas-phase reaction products when 2MB was exposed to Cl and sunlight. The atmospheric implications will be discussed in terms of lifetimes and reactions products.</p><p><strong>REFERENCES:</strong> <strong>1</strong>. Szwajkowska-Michale, L., Busko, M., Lakomy, P., and Perkowski, J.: Determination of profiles of volatile metabolites produced by Trametes versicolor isolates antagonistic towards Armillaria spp. Sylwan. <strong>2018</strong>, 162, 499–508. <strong>2. </strong>Kolar, P.; Kastner, J. R. Low-Temperature Catalytic Oxidation of Aldehyde Mixtures Using Wood Fly Ash: Kinetics, Mechanism, and Effect of Ozone. Chemosphere. <strong>2010</strong>, 78 (9), 1110–1115. <strong>3. </strong>D’Anna, B.; Andresen, O.; Gefen, Z. and Nielsen, C.J.: Kinetic study of OH and NO<sub>3</sub> radical reactions with 14 aliphatic aldehydes. Phys.Chem.Chem.Phys. <strong>2001</strong>, 3, 3057-3063. <strong>4. </strong>Wenger, J.C.: Chamber Studies on the Photolysis of Aldehydes. Environmental Simulation Chambers: Application to Atmospheric Chemical Processes. <strong>2006. </strong>Nato Science Series: IV: Earth and Environmental Science, vol 62. Springer, Dordrecht. <strong>5. </strong>Antiñolo, M.; Asensio, M.; Albadalejo, J. and Jiménez E.: Gas-Phase Reaction of trans-2-methyl-2-butenal with Cl: Kinetics, Gaseous Products, and SOA Formation. Atmosphere <strong>2020</strong>, 11 (7), 715. <strong>6. </strong>Blázquez, S.; Antiñolo, M.; Nielsen, O. J.; Albadalejo, J. and Jiménez, E.: Reaction kinetics of (CF<sub>3</sub>)<sub>2</sub>CFCN with OH radicals as a function of temperature (278-358 K): A good replacement for greenhouse SF<sub>6</sub>? Chem.Phys.Lett. <strong>2017</strong>, 687, 297-302.</p>

Kinetic study by mass spectrometry and calculation of the enthalpy of decomposition of basic nickel carbonate

1989 ◽  
Vol 152 (2) ◽  
pp. 329-334 ◽  
Author(s):  
M.M. Romero ◽  
J.C. Llópiz ◽  
A. Jerez ◽  
C. Pico ◽  
M.L. Veiga
Keyword(s):  
Mass Spectrometry ◽  
Kinetic Study ◽  
Nickel Carbonate

Comparison of different advanced oxidation process to reduce toxicity and mineralisation of tannery wastewater

2004 ◽  
Vol 50 (5) ◽  
pp. 329-334 ◽  
Author(s):  
S.G. Schrank ◽  
H.J. José ◽  
R.F.P.M. Moreira ◽  
H. Fr. Schröder
Keyword(s):  
Mass Spectrometry ◽  
Organic Compounds ◽  
Advanced Oxidation Process ◽  
Specific Treatment ◽  
Advanced Oxidation ◽  
Tannery Wastewater ◽  
Treated Wastewater ◽  
Gas Chromatography Mass Spectrometry ◽  
Oh Radicals ◽  
Untreated Wastewater

Many organic compounds contained in wastewater are resistant to conventional chemical and/or biological treatment. Because of this reason different degradation techniques are studied as an alternative to biological and classical physico-chemical processes. Advanced Oxidation Processes (AOPs) probably have developed to become the best options in the near future. AOP while making use of different reaction systems, are all characterised by the same chemical feature: production of OH radicals (*OH). The versatility of AOPs is also enhanced by the fact that they offer different possibilities for OH radical production, thus allowing them to conform to specific treatment requirements. The main problem with AOPs is their high cost. The application of solar technologies to these processes could help to diminish that problem by reducing the energy consumption required for generating UV radiation. In this work, different AOPs (O3, TiO2/UV, Fenton and H2O2/UV) were examined to treat tannery wastewater or as a pre-treatment step for improving the biodegradation of tannery wastewater, at different pH and dosage of the chemicals. Under certain circumstances retardation in biodegradation and/or an increase in toxicity may be observed within these treatment steps. Two different bioassays (Daphnia magna and Vibrio fischeri) have been used for testing the progress of toxicity during the treatment. In parallel other objectives were to analyse and identify organic compounds present in the untreated wastewater and arising degradation products in AOP treated wastewater samples. For this purpose substance specific techniques, e.g., gas chromatography - mass spectrometry (GC-MS) in positive electron impact (EI(+)) mode and atmospheric pressure ionisation (API) in combination with flow injection analysis (FIA) or liquid chromatography - mass and tandem mass spectrometry (LC-MS or LC-MS-MS) were performed.

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