Mechanistic study of interactions between photo-oxidation and biodegradation of n-nonylbenzene in seawater

Abstract. Methane sulphonamide (MSAM), CH3S(O)2NH2, has recently been detected for the first time in ambient air over the Red Sea and the Gulf of Aden where peak mixing ratios of ~ 60 pptv were recorded. Prior to this study the rate constant for its reaction with the OH radical and the products thereby formed were unknown, precluding assessment of its role in the atmosphere. We studied the OH-initiated photo-oxidation of MSAM in air (298 K, 700 Torr total pressure) in a photochemical reactor using in situ detection of MSAM and its products by FTIR absorption spectroscopy. The relative rate technique, using three different reference compounds, was used to derive a rate coefficient of (1.4 ± 0.3) ×10−13 cm3 molecule−1 s−1. The main end products of the photo-oxidation observed by FTIR were CO2, CO, SO2 and HNO3 with molar yields of (0.73 ± 0.11), (0.28 ± 0.04), (0.96 ± 0.15) and (0.62 ± 0.09), respectively. N2O and HC(O)OH were also observed in smaller yields (0.09 ± 0.02), (0.03 ± 0.01). Both the low rate coefficient and the products formed are consistent with hydrogen abstraction from the -CH3 group as the dominant initial step. Based on our results MSAM has an atmospheric lifetime with respect to loss by reaction with OH of about 80 days.

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Mechanistic study on the photo-oxidation of α-diketones

Tetrahedron ◽

10.1016/s0040-4020(01)96593-7 ◽

1985 ◽

Vol 41 (11) ◽

pp. 2199-2205 ◽

Cited By ~ 15

Author(s):

Yasuhiko Sawaki

Keyword(s):

Mechanistic Study ◽

Photo Oxidation

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Mechanistic study of the role of Au, Pd and Au–Pd in the surface reactions of ethanol over TiO2 in the dark and under photo-excitation

Catalysis Science & Technology ◽

10.1039/c7cy00961e ◽

2017 ◽

Vol 7 (22) ◽

pp. 5301-5320 ◽

Cited By ~ 11

Author(s):

Shahid Bashir ◽

Hicham Idriss

Keyword(s):

Infrared Spectroscopy ◽

Surface Reactions ◽

Catalytic Reactions ◽

Mechanistic Study ◽

Pd Catalysts ◽

Photo Oxidation

In situ infrared spectroscopy (FTIR) and catalytic reactions are employed to explore the photo-oxidation and photo-reforming of ethanol over TiO2 and M/TiO2 (M = Au, Pd and Au–Pd) catalysts.

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Kinetic and mechanistic study of the reaction between methane sulfonamide (CH3S(O)2NH2) and OH

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-2695-2020 ◽

2020 ◽

Vol 20 (5) ◽

pp. 2695-2707 ◽

Cited By ~ 2

Author(s):

Matias Berasategui ◽

Damien Amedro ◽

Achim Edtbauer ◽

Jonathan Williams ◽

Jos Lelieveld ◽

...

Keyword(s):

Rate Coefficient ◽

Relative Rate ◽

Hydrogen Abstraction ◽

Initial Step ◽

Ambient Air ◽

Mechanistic Study ◽

Photo Oxidation ◽

Mixing Ratios ◽

In Situ Detection ◽

First Time

Abstract. Methane sulfonamide (MSAM), CH3S(O)2NH2, was recently detected for the first time in ambient air over the Red Sea and the Gulf of Aden where peak mixing ratios of ≈60 pptv were recorded. Prior to this study the rate constant for its reaction with the OH radical and the products thereby formed were unknown, precluding assessment of its role in the atmosphere. We have studied the OH-initiated photo-oxidation of MSAM in air (298 K, 700 Torr total pressure) in a photochemical reactor using in situ detection of MSAM and its products by Fourier transform infrared (FTIR) absorption spectroscopy. The relative rate technique, using three different reference compounds, was used to derive a rate coefficient of (1.4±0.3)×10-13cm3molec.-1s-1. The main end products of the photo-oxidation observed by FTIR were CO2, CO, SO2, and HNO3 with molar yields of (0.73±0.11), (0.28±0.04), (0.96±0.15), and (0.62±0.09), respectively. N2O and HC(O)OH were also observed in smaller yields of (0.09±0.02) and (0.03±0.01). Both the low rate coefficient and the products formed are consistent with hydrogen abstraction from the −CH3 group as the dominant initial step. Based on our results MSAM has an atmospheric lifetime with respect to loss by reaction with OH of about 80 d.

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