Abstract: By using a polytetrafluorethylene(PTFE) emulsion as fluorinating reagent, a method for fluorinating assisted eletrothermal vaporization (ETV)/ICP-AESdirect determination of trace yttrium in TiO₂ ceramic powder has been proposed; the various facts which would affect the vaporization process between the matrix and the analyte were studied ; the fluorinating vaporization behavior of the matrix and the analyte both in slurry and in solution were investigated. Based on pre-separation between the matrix and the analyte, the matrix effect was reduced. On the optimum experiment conditions, the detection limit of the present method is 0.26μg/L; and the RSDis 3.8 % (n=5, c=0.5 mg/L). This method has been applied to directly determinate trace yttrium in two kinds of TiO₂ powder without any chemical pretreatment.

Key words: Fluorination electrothermal vaporization, Slurry sampling, ICP-AES, Trace impurity yttrium