Infrared gas phase spectrometry for oxygen and hydrogen sulfide by UV photolysis

Oxygen, hydrogen sulfide and other weakly IR-absorbing compounds have been analyzed indirectly by photochemical conversion into other IR-active substances. Oxygen, when irradiated with intense UV light, is converted into ozone, which gives an absorption band centered at 1043 cm(-1). Hydrogen sulfide, a weak IR absorber, is converted into sulfur dioxide, with a band centered at 1361 cm(-1). Both ozone and sulfur dioxide have intense infrared spectral absorptions free from water or carbon dioxide interference. However, if this indirect method is to be employed for chemical determinations other factors must be considered. Methyl ethyl ketone and benzene have been investigated for their effect on conversion rates and percent conversion of oxygen into ozone. H2S is converted into sulfur dioxide, but the SO2 is subsequently dissociated. Results for oxygen and hydrogen sulfide determinations by use of various parameters will be discussed.