Investigation of vaporization/condensation processes in electrothermal atomizer for analytical spectrometry

Fractional structure of aerosols formed in the electrothermal vaporiser from the solutions of cadmium nitrate, copper nitrate and sodium chloride with the longitudinally heated graphite tube was investigated by using the methods of atomic-force microscopy. Transfer of aerosols onto substrate was performed by means of method of electrostatic precipitation in the corona discharge. It was shown that with decrease of volatility of the analyte the size of aerosol particles increases. Evaporation of 2 $\mu$g NaCl creates the aerosol with 200–900 nm size particles which could be centers of condensation of analyte. It was shown that reduction of matrix influence on formation of aerosol can be achieved through two-stage vaporization with intermediate stage of fractional condensation.