The vaporization behavior of silicon and three refractory trace elements (Al, Ti and Y) were studied in the presence and absence of a PTFE emulsion as fluorinating reagent and applying an electrothermal ICP-AES coupled system.It was found that during a 60 s ashing step at 700℃ about 90% of 100mg of Si3N4 can be decomposed and evaporated without considerable losses of the trace elements investigated. Calibration could be carried out by the standard addition method and the calibration curve method applying spiked slurries and aqueous standard solutions with peak height intensity measurements, respectively. The detection limits varied from 0.11 mg g−1 (Al) to 0.09mg g−1 (Ti) with RSD 1.9-4.2%.