Mass spectrometric study of ion/molecule reaction in methane and ammonia mixtures

Ion/molecule reactions initiated by electron impact in ammonia-methane mixtures have been studied by means of quadrupole mass spectrometer with a high-pressure ion source. The total pressure of the mixtures was ranged from 0.5 to 33.3 Pa. Measurements were performed for different concentrations of ammonia and methane in the mixture (from 10% CH4+90% NH3 to 90% CH4+10% NH3 with 10% increment). The major ion/molecule reactions have been identified. Relative ion intensities for the observed ions were determined as a function of total gas pressure inside the ion source collision chamber and concentration of methane in the mixture.