Ozone modified beta radioactive ion source and application thereof

The invention relates to an ion source in an analytical instrument, in particular to a beta radioactive ion source modified by ozone. A part of O2 in clean air is firstly translated into O3 through an ozone generating device and then enters the beta radioactive ion source, and O2-(H2O)n reagent ions generated by the clean air in the beta radioactive ion source are reacted with O3 to generate new reagent ions O3-(H2O)n. The new generated reagent ions can not only generate electron transfer reaction with electronegative compounds (such as explosive some substances and halogen compounds), but also generate O- transfer reaction with some components (such as SO2 and CO2), so that number of the channels of compound ionizing in the beta radioactive ion source are increased, and the enlargement of detectable range of the compounds can be benefited.