不用切口的示波极谱滴定法

Oscillopolarographic Titrations Without Incisions

利用示波极谱图上切口的出现或消失来指示滴定终点的示波极谱滴定法具有终点直观、操作简便、仪器简单和抗干扰能力强等优点,但此法要求试剂能在示波极谱图上产生敏锐的切口。在微铂电极和铂片电极上进行示波极谱氧化还原滴定时,人们往往看到在滴定终点整个示波图发生突然变化,这种变化包括整个示波图的骤然扩大或缩小以及示波图位置的骤然移动。这种整个示波图的变化如此突然、灵敏,完全可用来指示滴定终点。在这里并不要求试剂在示波极谱图上产生切口。

Oscillopolarographic titrations are usually carried out on Hg or Pt electrode using the appearance or disappearance of the incisions to indicate the end point of titration.This requires the reagent to give oscillopolarogram with sensitire incision.This paper reports that oscillopolarographic titrations can be carried out on Pt electrodes using the sudden change of the whole oscillogram(increase or decrease in size,shift in position)to indicate the end point.This is very common in redox titrations.The titrations of Cu^(2+) with EDTA,Cl^(-) with AgNO_(3) and many neutralization titrations as well as redox titrations can be carried out in this way.