MULTI-ELEMENT ANALYSIS OF TELLURIUM DIOXIDE WITH PRELIMINARY SEPARATION OF THE SAMPLE MATRIX BY REACTIVE DISTILLATION

A method for separating the sample matrix of tellurium dioxide TeO is proposed, based on reactive distillation in a flow reactor, in the form of tellurium tetrachloride at 240°C; the chlorinating agent is gaseous chlorine. The behavior of 59 impurities was studied, it was found that As, Au, B, Bi, Cu, Ga, In, Mo, Nb, Pb, Re, Ru, Sb, Se, Sn, Ta, Ti, V, W and Zn are lost completely or partially; Ag, Al, Ba, Be, Ca, Cd, Ce, Co, Cr, Dy, Er, Eu, Gd, Ir, Hf, Ho, K, La, Li, Lu, Mg, Mn, Na, Nd, Ni, P, Pd, Pr, Pt, Rb, Rh, Sc, Sm, Sr, Tb, Tm, Y, Yb and Zr are retained in the concentrate by more than 75 %. The impurity content in the concentrates was determined by inductively coupled plasma atomic emission spectrometry. The accuracy was confirmed by the added-found method and comparison with the results of analysis without concentration. The limits of detection are in the range from 2 × 10 to 8 × 10 wt. %, the intralaboratory precision does not exceed 31 %.