Ti(Ⅳ)-TAR-NaBrO_3体系极谱吸附催化波的研究

STUDIES ON THE POLAROGRAPHIC ADSORPTIVE CATALYTIC WAVE OF TITANIUM(Ⅳ)-TAR-NaBrO_3 SYSTEM

在pH 4.7的HOAc—NaOAc缓冲溶液中,Ti(Ⅳ)—TAR—NaBrO_3体系产生一灵敏的极谱吸附催化波,峰电位为-0.90V(vs.SCE)左右,Ti(Ⅳ)浓度在2.0×10^(-9)～1.3×10^(-6)mol·L^(-1)范围内与峰电流呈线性关系,络合物的络合比为Ti(Ⅳ):TAR=1:1。研究了极谱波的性质和电极反应机理,并用此法测定了铝合金样品中的痕量钛,结果满意。

In a 0. lmol ·L^(-1) acetate buffer solution containing 4. O×10^(-5)mol ·L^(-1) TAR and 0. 025mol ·L^(-1) NaBrO_3 at pH 4. 7, a sensitive polarographic adsorptive catalytic wave of Ti(N ) TAR complex was observed by using single-sweep polarography. The peak potential is. 90V(vs.SCE). The peak height is proportional to the concentration of Ti(IV ) over the concentration range of Ti( I ) of 2.0×10^(-9)~1.3×10^(-6)mol ·L^(-1). The limit of detection is 1×10^(-9)mol ·L^(-1) for Ti( IV ). The mechanism of the electrode reaction is studied. The method has been applied to the determination of titanium in aluminum alloys with satisfactory results.