【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%。更多还原

【Abstract】 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 KIO₄ 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%.更多还原