Aerodynamic thermal breakup droplet ionization combined with a β-irradiation source for mass-spectrometric analysis of samples in a nonpolar solvent

A method is proposed for increasing the number of ions during mass-spectrometric analysis of samples in a nonpolar solvent (benzene). For this purpose, aerodynamic thermal breakup droplet ionization (ATBDI) with the impact of β-radiation on the aerosol droplets used in ATBDI was evaluated. This modification of the method, which we named β-ATBDI, allows to shift a nonvolatile analyte (trinitrotoluene in the negative ionization region and cocaine in the positive ionization region, as an example) into a gas phase as an aerosol at room temperature (in contrast to atmospheric pressure chemical ionization). In addition, β-ATBDI enables a researcher to distinguish mass spectrometric peaks of the compounds located in an aerosol droplet from compounds located outside the droplet, i.e., to identify background peaks. Also briefly discussed the ionization of two antibiotics-azithromycin in methylene chloride and sulfadiazine in salt water with β-ATBDI, ATBDI and electrospray ionization source.