四氯络汞(Ⅱ)离子电极的研制及其应用研究

Studies on Preparation and Application of Mercury(Ⅱ)Tetrachloride Anion Selective Electrode

以十六烷基双硫腙·四氯络汞 (Ⅱ )为载体 ,制备了PVC膜四氯络汞 (Ⅱ )阴离子选择性电极 ;测定了40多种金属离子以及阴离子的选择性 ,除Sn(Ⅳ)、Sb(Ⅲ )稍有干扰外 ,其它金属离子均无明显的干扰 ;25℃时 ,1mol·L-1 NaCl-1×10-3 mol·L-1HCl溶液中 ,汞(Ⅱ)浓度在6×10-6～1.0×10-2 mol·L-1 呈线性响应 ,斜率为31±2mV/decade,检出限为4×10 -6mol·L -1;用电位法测得汞在蔬菜中的回收率为92.5%～97.2 % ,相对标准偏差在0.8 %～1.6 %范围 ;该法用于绿萍、莴笋、丝瓜等中微量汞的含量测定 ,结果令人满意。

Studies on preparation and applications of polyvinyl chloride membrane mercury(Ⅱ)tetrachloˉride anion selective electrode based on a carrier S -hexadecyl diphenylthiocarbazone·HgCl 4 were reported in this paper.More than forty inorganic metallic ions and anions were examined and it was found only Sn(Ⅳ)and Sb(Ⅲ)showa little interference.At25℃,the linear response range of the electrode for merˉcury(Ⅱ)was6×10 -6 to1.0×10 -2 mol·L -1 ,with a slope of31±2mV/decade in1×10 -3 mol·L -1 HCl-1mol·L -1 NaCl solution.The detection limit was4×10 -6 mol·L -1 .The recovery for the mercury determination in vegetables by potential method was in the range of92.5%～97.2%and the relative standard deviation was in the range of0.8%～1.6%.This method was applied to the determiˉnation of trace mercury in azolla filiculoides,asparagus lettuce and vegetable sponge with satisfactory results.