ABSTRACT
In this paper the results of vacuum sublimation experiments are presented and discussed. Vacuum sublimation experiments show that only low concentrations of PAH can be
detected in six of the seven fly ashes under investigation. Sublimation at high temperature (175°C) leads to a decrease of the extraction efficiency in comparison with sublimation at 60 or even at 30°C. Although the cause of this effect has not been investigated, it is probable that chemical conversion of the PAH on the fly ash surface gives rise to this phenomenon. The fly ash with considerable amounts of PAH deviates from this behaviour, i.e. the collected amounts of PAH are higher at 175°C than at 60 or 30°C.
