. Can. J. Chem. 59,2750Chem. 59, (1981.The photolytic oxidation of methyl mercaptan, dimethyl sulphide, and dimethyl disulphide was studied in a batch photolysis apparatus. Short wavelength ultraviolet light was provided by a deuterium discharge lamp and monitored by a monochromator equipped with an extended response photomultiplyer tube. Sulphide concentrations were determined using a gas chromatograph equipped with a flame photometric detector having a sulphur response at 365 nm.The rate of photo-oxidation of methyl mercaptan was found to be a linear function of the photon absorption rate and exhibited a quantum yield of 12. The methyl mercaptan photo-oxidation rate was found to be unaffected by increased oxygen concentration, decreased atmospheric pressure, or the presence of sulphur dioxide.The quantum yield of dimethyl sulphide photo-oxidation was found to be dependent upon air pressure; the quantum yield of 4 at 1 atm pressure increased to 8 at batm.The quantum yield of dimethyl disulphide photo-oxidation in air was found to be 1. On trouve que la vitesse d'oxydation photochimique du methylmercaptan est lineaire en fonction de la vitesse d'absorption du photon et presente un rendement quantique de 12. On a trouve que la vitesse d'oxydation photochimique du methylmercaptan n'est pas affectee par une augmentation de la concentration en oxygene, par la diminution de la pression atmospherique ou par la presence du bioxyde de soufre.On a trouve que le rendement quantique de I'oxydation photochimique du sulfure de dimethyle depend de la pression d'air; le rendement quantique qui est de 4 a la pression atmospherique passe 8 une pression de 0,25 atmosphere.Dans le cas du disulfure de dimethyle le rendement quantique dans I'air est de 1.9 a la pression atmospherique pour une concentration en disulfure de 7,04 x M .[Traduit par le journal]

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