钪(Ⅲ)-氯代磺酚-S络合吸附波及其分析应用

Complex Adsorptive Wave of Scandium (Ⅲ)-Chlorosulfophenol-S and Its Analytical Application

在含少量水杨酸的NaAc-HAc-HCl(pH 2)介质中,钪(Ⅲ)和氯代磺酚-S(CSP-S)形成有电活性的络合物,于-0.39V(vs.SCE)处出现一灵敏的二次导数极谱电流峰.电流峰高(i_p)和抗(Ⅲ)浓度在4.5×10^-8～5.3×10^-6 mol/L范围内呈线性关系,相关系数(r)为0.9992,检出限为2.5×10^-8mol/L Se(Ⅲ).方法用于高温合金中微量钪的测定,结果满意.[SE(Ⅲ)]:[CSP-S]=1:1,表观稳定常数(k)为 3.2×10~6.至少稳定36h.较详细研究了络合物存在形态、电流特性、电极过程可逆性、电极反应机理,探讨进一步增敏的可能性.

An electroactive complex of scandium (Ⅲ) with chlorosulfophenol-S( CSP-S) was formed inthe medium of NaAc - HAc - HCl(pH 2) including micro amounts of salicylic acid and then a sensitivesecond derivative oscillopolarographic peak current (P) appeared at-0. 39 V (vs.SCE). The peakcurrent (inp) was proportional to the concentration of scandium (Ⅲ) in the range of 4.5×10～8-5.3×10-6mol/L, the correlation coefficient( r) and detection limit were 0.9992 and 2.5×10-8mol/L Sc(Ⅲ)respectively. The proposed method has been applied to determine the micro scandium in superalloy withsatisfactory results. The molar ratio of [So(Ⅲ)] to [CSP-S] was 1:1, the apparent stability constant(k) was calculated to be 3.2×106. The system was steady at least for 36 h. The existing form of thecomplex, the character of the current, the reversibility of the electrode process and the mechanism of electrode reaction were investigated in detail. The possibility for the further sensitization was discussed.