甲基紫电极EDTA电位滴定法测定微量铅  

Determination of trace leadⅡ by EDTA potential titration using methyl violet ion selective electrode

作　　者：何智娟[1] 董学芝[1] 胡卫平[1] 

机构地区：[1]河南大学化学化工学院,河南开封475001

出　　处：《冶金分析》2005年第2期6-9,共4页Metallurgical Analysis

摘　　要：提出了在氨三乙酸(NTA,活化剂)存在下,以Mn 催化高碘酸钾氧化甲基紫的反应指示滴定终点,以自制的甲基紫选择性电极为指示电极,Mn 为滴定剂,EDTA为阻抑剂,催化电位滴定法测定微量铅的新方法。实验表明,选择1 0×10-3mol/L甲基紫溶液、5 0×10-3mol/LKIO4溶液和5 0×10-3mol/LNTA溶液用量分别为0 50,1 00,0 50mL,滴定速度1 7mL/min,终点灵敏,准确度高。将该方法用于蓄电池废水中铅含量测定,结果与火焰原子吸收光谱法一致,样品平均回收率为99 1%,RSD为1 47%。A new potential titration with catalytic indicating end point for the determination of trace lead is described. Based on the catalytic effect of manganese*' on the oxidation of methyl violet(MV) by potassium periodate in the presence of nitrilotriacetic acid(NTA), a new kind of methyl violet ion selective electrode made by ourselves is used for inspecting the change of potential,and manganese*' is served as a titrant and EDTA is served as a inhibitor in the titration.The results show when the volume of 1.0×10^(-3) mol/L MV solution,5.0×10^(-3) mol/L KIO_4 solution,5.0×10^(-3) mol/L NTA solution is 0.50,1.00,0.50 mL respectively,and the chosen rate of titration is 1.7 mL/min.The method has high sensitivity and good accuracy.It has been applied to the determination of lead*' in the waste water of storage battery and the results determined by this method is agreed with those by atomic absorption spectrometry.The average recovery of sample is 99.1%,and the relative standard deviation is 1.47%.

关 键 词：滴定法测定 EDTA 甲基紫 电位 微量铅 火焰原子吸收光谱法 Mn(Ⅱ) 选择性电极 铅含量测定 平均回收率 氨三乙酸 滴定终点 反应指示 高碘酸钾 指示电极 铅(Ⅱ) KIO4 滴定速度 活化剂 滴定剂 溶液 NTA min 准确度 蓄电池 

分 类 号：X830[环境科学与工程—环境工程] O657.15[理学—分析化学]