title: Products of the gas-phase reactions of OH radicals with (C2H5O)2P(S)CH3 and (C2H5O)3PS.
abstract: Products of the gas-phase reactions of OH radicals with O,O-diethyl methylphosphonothioate [(C2H5O)2P(S)CH3, DEMPT] and O,O,O-triethyl phosphorothioate [(C2H5O)3PS, TEPT] have been investigated at room temperature and atmospheric pressure of air using in situ atmospheric pressure ionization mass spectrometry (API-MS) and, for the TEPT reaction, gas chromatography and in situ Fourier transform infrared (FT-IR) spectroscopy. Combined with products quantified previously by gas chromatography, the products observed were: from the DEMPT reaction, (C2H5O)2P(O)CH3 (21+/-4% yield) and C2H5OP(S)(CH3)OH or C2H5OP(O)(CH3)SH (presumed to be C2H5OP(O)(CH3)SH by analogy with the TEPT reaction); and from the TEPT reaction, (C2H5O)3PO (54-62% yield), SO2 (67+/-10% yield), CH3CHO (22-40% yield) and, tentatively, (C2H5O)2P(O)SH. The FT-IR analyses showed that the formation yields of HCHO, CO, CO2, peroxyacetyl nitrate [CH3C(O)OONO2], organic nitrates, and acetates from the TEPT reaction were <5%, 3+/-1%, <7%, <2%, 5+/-3%, and 3+/-2%, respectively. Possible reaction mechanisms are discussed.
authors.affiliation: Air Pollution Research Center, University of California, Riverside, California 92521, USA.
authors.forename: Ernesto C
authors.initials: EC
authors.lastname: Tuazon
authors.forename: Sara M
authors.initials: SM
authors.lastname: Aschmann
authors.forename: Roger
authors.initials: R
authors.lastname: Atkinson
mesh_terms: D001272:Atmosphere / Q000737:chemistry; D005740:Gases / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry*; D063086:Organothiophosphates / Q000737:chemistry*; D009946:Organothiophosphorus Compounds / Q000737:chemistry*; D011312:Pressure; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
chemical_list: D005740:Gases; C519088:O,O-diethyl methylphosphonothioate; D063086:Organothiophosphates; D009946:Organothiophosphorus Compounds; C052516:O,O,O-triethyl phosphorothioate; D017665:Hydroxyl Radical